Complete Guide to Ecommerce Advertising: Channels, Feeds and EU Rules

Ecommerce advertising is paid promotion that puts specific products in front of people who are ready to buy: Shopping ads and Performance Max on Google, catalog ads on Facebook and Instagram, and sponsored listings inside marketplaces such as Amazon. All three run on the same raw material, a clean product feed, and all three are judged by the same rules on prices, discounts, delivery and environmental claims. This guide covers each channel, how to prepare the feed, how to write product ad copy, and the EU and US rules that apply as of October 2026.

1. The three engines of ecommerce advertising

Most stores that advertise use some mix of three systems, and each behaves differently.

• Search and shopping (mainly Google): captures demand that already exists. Someone searches for "waterproof hiking boots women size 39" and your product appears with an image and a price.
• Social catalog ads (mainly Meta on Facebook and Instagram): creates demand and brings back visitors. People are not searching, but the platform can show each person products they viewed or similar ones.
• Marketplace ads (for example Amazon Sponsored Products): promotes your listings inside a store where shoppers are already comparing products. You compete on price, reviews and availability as much as on the ad.

A small store rarely needs all three on day one. Start where buying intent already exists, then add social catalog ads once you have enough traffic for retargeting to work.

2. Channel comparison

Channel	What it needs	Where ads appear	How targeting works	Best first use
Google Standard Shopping	Merchant Center account with an approved product feed, linked to Google Ads	Shopping tab, Search results, Images, search partners	No keywords; Google matches searches to your product data	A simpler start that stays on Google's shopping surfaces
Google Performance Max (with a Merchant Center feed)	The same feed, plus conversion tracking and ideally text, image and video assets	All Google Ads inventory: Search, Shopping, YouTube, Display, Discover, Gmail, Maps	Goal-based automation driven by your conversion data	Scaling once conversion tracking is reliable
Meta Advantage+ catalog ads	A catalog in Commerce Manager, Meta Pixel or Conversions API sending ViewContent, AddToCart and Purchase with matching product IDs	Facebook, Instagram and Meta's other placements	Shows products based on what people viewed or on similar interests	Retargeting product viewers and broad prospecting with the full range
Amazon Sponsored Products	A professional seller or vendor account and listings eligible for the Featured Offer	Amazon search results, product detail pages, and some placements beyond Amazon	Manual or automatic keywords, plus product targeting	Products already sold on Amazon with competitive prices and reviews

Each of these runs on an auction with a budget you set. Your real cost is that budget plus the time needed to keep the feed and the ads accurate, and on marketplaces any selling-plan fees you already pay.

3. Google: Merchant Center, Shopping and Performance Max

Merchant Center is the foundation

Google's Shopping ads do not use keywords. They use the product data you submit in Google Merchant Center: title, description, price, image, availability and identifiers. Before you can run Shopping ads or Performance Max with a product feed, Merchant Center needs your business details, a verified website and approved products, and it must be linked to your Google Ads account. Google also notes that you cannot change the linked Merchant Center account after a campaign is created, so pick the right one at the start.

Set up Shipping and returns in Merchant Center too. Shipping costs, handling time, order cut-off time and return policies (return window, return fees, refund processing time) are configured there and shown to shoppers. If those settings promise something your checkout does not deliver, you have an accuracy problem before any ad copy is written.

Standard Shopping or Performance Max?

Two campaign types can serve Shopping ads. Standard Shopping keeps your ads on Google's shopping surfaces: the Shopping tab, Search results, Images and search partner sites. Performance Max is a goal-based campaign that can use all Google Ads inventory from one campaign, including YouTube, Display, Gmail and Maps, and it relies heavily on your conversion data to decide where to spend. If conversion tracking is weak or consent rates are low, Performance Max has little to learn from, so many stores start with Standard Shopping or a small Performance Max test and grow from there.

As of October 2026 Google is also testing AI Max for Shopping campaigns in beta, which can customise Shopping ad text such as product titles (English feeds only at the time of writing) and, with Final URL expansion, send shoppers to other landing pages. Review generated text as you would copy written by a person: the price and claim rules below apply to whatever appears in the ad.

Selling in Europe: Comparison Shopping Services

In a list of European countries that includes Germany, France, Italy, Spain, the Netherlands, Poland, Denmark, Sweden, Finland, Norway, Switzerland and the UK, Shopping ads and free product listings on Google's general search results are placed through a Comparison Shopping Service (CSS). You can use Google Shopping itself as your CSS, use another CSS, or use several at once. The CSS pays Google for clicks and sets its own terms with you, so compare the terms before you choose. For the account-level privacy settings, see our Google Ads GDPR settings guide and the Google Ads automation guide.

4. Meta: catalog ads and Advantage+ campaigns

Meta's product ads are called Advantage+ catalog ads (previously known as dynamic ads). They need three things working together:

1. A catalog in Commerce Manager. Items can be added through a data feed file (CSV, TSV, RSS XML, ATOM XML or Google Sheets), uploaded once or on an hourly, daily or weekly schedule, or updated through Meta's Batch API.
2. An event source: the Meta Pixel, the Conversions API, or both, sending at least ViewContent, AddToCart and Purchase events.
3. Matching IDs. The content_ids sent with each event must match the item IDs in the catalog. If your site sends a variant SKU while the catalog uses a parent ID, the ads cannot connect a visitor to the product they viewed.

Meta has also moved its automated campaign setup to a single Advantage+ structure for sales, app and leads objectives. The older Advantage+ shopping campaign type is being retired: Meta's developer notices say these campaigns can no longer be created or updated through the Marketing API, and that all remaining ones would be paused with Marketing API version 26.0, which Meta released on 29 July 2026. If you still run one, rebuild it as an Advantage+ campaign on the Sales objective.

In the EU, the Pixel and the Conversions API both raise consent questions. Our Facebook and Instagram GDPR guide and the social media advertising guide cover the setup in detail.

5. Marketplace ads

If you already sell on a marketplace, its own ad program puts you in front of shoppers who are comparing products. Amazon's Sponsored Products are cost-per-click ads for individual listings. They appear in search results and on product detail pages, with keyword targeting that you choose manually or let Amazon pick automatically, plus product targeting. They are open to professional sellers, vendors and some other account types, and a listing generally has to be eligible for the Featured Offer to be advertised. Other large marketplaces run similar retail media programs; check each one's eligibility rules before you plan a budget.

An ad cannot fix a weak listing: if your price, reviews or delivery time lose against the product next to yours, the click is wasted. The price and claim rules below apply to marketplace listings too.

6. Product feed basics

Shopping ads, catalog ads and marketplace listings all read from your product data, so the feed is the biggest lever you have. Google's product data specification is a useful baseline.

Attribute	Status in Google Merchant Center	What good looks like
id	Required, max 50 characters, unique per product	Stable over time and identical to the ID your site sends in tracking events
title	Required, max 150 characters	Brand, product type, key attributes (size, colour, material, model) in the order shoppers search
description	Required, max 5,000 characters	Facts about the product: materials, dimensions, use, care. No promotional text or prices
link and image_link	Required	The exact product page; a clean main image of the actual item
availability	Required	in_stock, out_of_stock, preorder or backorder, kept in sync with the site
price	Required	The same price, in the same currency, that the checkout charges
sale_price and sale_price_effective_date	Optional	Used only for real reductions, with start and end dates (see the EU prior-price rule below)
brand, gtin, mpn	Brand required for most new products; GTIN strongly recommended where it exists; MPN if there is no GTIN	Real manufacturer identifiers, never invented ones
condition	Required for used or refurbished items	new, refurbished or used

Feed checklist

• Prices, availability and shipping in the feed match the landing page and the checkout.
• Product IDs in the feed match the IDs in your Pixel, Google tag and Conversions API events.
• Titles start with what shoppers type, not with a slogan.
• Sale prices carry effective dates, so they end automatically when the promotion ends.
• Every variant (size, colour) that you want advertised is its own item with its own attributes.
• You have a routine for updates: a scheduled feed URL, an export from your shop system, or a manual upload you actually repeat.

7. Writing ad copy for products

Shopping and catalog ads take most of their text from the feed, but you still write search ads, catalog ad primary text, Performance Max headlines and marketplace bullet points, each with its own limits. Google's responsive search ads, for example, take up to 15 headlines of 30 characters and up to 4 descriptions of 90 characters.

Good product ad copy does four jobs in a small space:

1. Names the product precisely: "Merino wool hiking socks, 3 pairs", not "Comfort for every adventure".
2. Gives one concrete reason to buy. A material, a measured feature, a size range, a warranty term you actually offer.
3. States the offer accurately. Price, delivery and returns exactly as they are at checkout, with no conditions hidden on another page.
4. Avoids claims you cannot prove. "Best", "number one", "lowest price anywhere", "clinically proven", "eco-friendly" all need evidence you can produce on request, and some are banned outright in the EU without it.

Write several versions per product group and let the platforms test them. Our ad creative and testing guide explains how to structure those tests so the results mean something.

8. Price and discount claims in the EU and US

EU: the 30-day prior-price rule

Since 28 May 2022, the EU's Omnibus Directive (EU) 2019/2161 has required that any announcement of a price reduction shows the prior price, defined as the lowest price the trader applied during a period of at least 30 days before the reduction. It inserted this rule as Article 6a of the Price Indication Directive 98/6/EC. In practice:

• A "was 89 EUR, now 59 EUR" ad needs the "was" figure to be the lowest price you charged in the 30 days before the sale started.
• A "-30%" badge is also a price reduction announcement, and the percentage should be calculated from that same prior price.
• Raising a price shortly before a sale so the discount looks bigger does not work: the lowest price in the window is the reference, not the most recent one.
• Member States may set different rules for goods that spoil or expire quickly, a shorter window for products on the market for less than 30 days, and a rule for progressive reductions during one sale. Check your national implementation if any of these apply.

A simple example: a jacket sold at 120 EUR for most of September, briefly cut to 99 EUR for a weekend, then returned to 120 EUR. If you announce a sale on 1 October, the prior price is 99 EUR, the lowest price in the previous 30 days. Advertising "was 120 EUR" would breach the rule.

The same directive also raised penalties under EU consumer law such as the Unfair Commercial Practices Directive: for widespread infringements covered by coordinated EU enforcement, national law must allow maximum fines of at least 4% of the trader's annual turnover in the Member States concerned. It also requires online stores to tell consumers when a price has been personalised on the basis of automated decision-making.

Other EU rules that touch promotions

The Unfair Commercial Practices Directive lists practices that are banned in all circumstances. Two matter for most stores: describing a product as "free" when the customer has to pay anything other than the unavoidable cost of responding and delivery, and falsely claiming that a product or offer is available only for a very limited time to push an immediate decision. Countdown timers that reset, or "last chance" offers that run all season, fall into that second category.

US: bona fide former prices

In the US there is no fixed 30-day window, but the FTC's Guides Against Deceptive Pricing (16 CFR Part 233) take a similar line. A former price comparison is legitimate when the former price is the actual, bona fide price at which the item was openly offered to the public on a regular basis for a reasonably substantial period of time. An inflated price set up only to advertise a large reduction makes the "bargain" deceptive. State laws can add more specific requirements, so check the states where most of your customers live.

9. Green claims as of October 2026

Directive (EU) 2024/825 on empowering consumers for the green transition is applied by national law from 27 September 2026; Member States had until 27 March 2026 to transpose it. It adds new practices to the EU blacklist of unfair commercial practices. From now on, the following are banned in all circumstances:

• Generic environmental claims where you cannot demonstrate recognised excellent environmental performance relevant to the claim. The directive's examples include "environmentally friendly", "eco-friendly", "green", "nature's friend", "ecological", "climate friendly", "carbon friendly", "energy efficient", "biodegradable" and "biobased".
• Sustainability labels that are not based on a certification scheme or established by public authorities. A self-designed "eco choice" badge on a product image falls here.
• Whole-product or whole-company claims when the benefit concerns only one aspect, for example calling a jacket "sustainable" because its lining is recycled.
• Offset-based neutrality claims: saying a product has a neutral, reduced or positive greenhouse gas impact because emissions were offset.
• Presenting legal requirements as a distinctive feature, such as advertising something every product in the category must have by law.

Claims about future environmental performance, such as "climate neutral by 2030", can be a misleading practice unless they rest on clear, public, verifiable commitments in a detailed implementation plan with measurable, time-bound targets that an independent expert verifies regularly.

What about the separate Green Claims Directive? The Commission announced in June 2025 that it intended to withdraw the proposal, and the European Parliament's legislative train lists the file as blocked as of September 2026. The rules above apply regardless.

What still works: specific, true, provable statements. "Shell made from 100% recycled polyester (certified)" with the certificate available, or "ships in a cardboard box with no plastic filler", can be fine if accurate. In the US, the FTC's Green Guides (16 CFR Part 260) already advise against unqualified general environmental benefit claims, so the same discipline serves both markets.

10. Returns and delivery promises in ads

Returns

Under the Consumer Rights Directive (2011/83/EU), EU consumers buying online have 14 days to withdraw from the contract without giving a reason, and the trader must refund payments, including standard delivery costs, within 14 days of being told. Two consequences for your ads:

• A bare "14-day returns" headline can present a legal right as if it were your own perk. The Unfair Commercial Practices Directive blacklists presenting rights given to consumers in law as a distinctive feature of the trader's offer. If you mention it, say it plainly as the statutory right, or advertise what you add on top.
• By default the consumer pays the direct cost of returning goods, unless you agreed to cover it or failed to tell them. So "free returns" and "30-day returns" are real advantages, but only if your returns policy, Merchant Center return settings and checkout all say the same thing.

Delivery

In the EU, unless a delivery time is agreed, the trader must deliver without undue delay and within 30 days of the contract. In the US, the FTC's Mail, Internet or Telephone Order Merchandise Rule requires a reasonable basis for any shipping time you advertise. If you state no time, you must reasonably expect to ship within 30 days, and if you cannot ship on time you must notify the customer, seek consent to the delay, or refund. "Next-day delivery" in an ad should be true for the products, regions and order times the ad actually reaches, with cut-off times stated where they apply.

11. Measurement with consent

In the EU, much of the conversion data that ecommerce campaigns learn from depends on consent. Google's EU user consent policy requires advertisers to obtain legally valid consent from users in the EEA, the UK and Switzerland for cookies where legally required and for the use of personal data to personalise ads. Google's consent mode passes the user's choice to Google tags using ad_storage, analytics_storage, ad_user_data and ad_personalization. In basic mode, tags do not load until the user interacts with the banner. In advanced mode, tags load with consent denied by default and send cookieless pings, which lets Google model conversions once a data threshold is met.

A practical setup:

1. A consent banner that blocks advertising tags until the user chooses, and where withdrawing consent is as easy as giving it. See the cookie consent guide and the consent management implementation guide.
2. Purchase conversions with value and currency in Google Ads, plus ViewContent, AddToCart and Purchase with product IDs for Meta.
3. Server-side events where they add accuracy, remembering that moving a tag to a server does not by itself remove the need for consent. Our server-side tracking article explains where the line is.
4. Retargeting audiences built only from users who agreed to advertising cookies; see GDPR retargeting.
5. A regular check of platform-reported sales against your shop's own order data, so you notice when attribution and reality drift apart.

12. Common mistakes

• Feed and site disagree on price, stock or shipping cost.
• Tracking IDs that do not match the catalog, so catalog ads cannot retarget properly.
• Inflated "was" prices, such as a recommended retail price shown as your own former price, instead of the lowest price of the prior 30 days for EU shoppers.
• Generic green words left over from old campaigns in ad libraries, product titles and image overlays.
• Advertising the legal 14-day withdrawal right as a perk instead of what you offer beyond it.
• Fake urgency. Countdown timers that restart and "only today" offers that run for weeks.
• Full automation without reliable conversion data. Performance Max and Advantage+ learn from your conversions; broken tracking teaches them the wrong lesson.
• Scaling spend before fixing the checkout, which just buys more abandoned carts.

13. What to do this week

1. Export your feed and compare 20 random products against their live product pages and checkout totals.
2. Check that the product IDs in your tracking events match catalog and feed IDs.
3. List every active discount ad and confirm the prior price for EU audiences is the lowest price of the previous 30 days.
4. Search your ad accounts, feed titles and creative overlays for generic environmental words and either remove them or replace them with specific, provable statements.
5. Line up your returns policy, Merchant Center return settings and ad copy so they say the same thing.
6. Confirm your consent banner, consent mode and Pixel behaviour for EU visitors, and test one purchase end to end.
7. Pick one channel to improve this month.

Where Adverizeo fits

Adverizeo writes product ad copy for 24 channels within each channel's format limits, and you can bring products in by CSV import. It does not sync with Shopify or product feeds, and it does not publish ads to ad managers; you export copy as CSV, Excel, JSON or text. Every text ad gets a compliance score from 0 to 100 with suggestions, which helps you catch risky wording before launch, but it is a risk check, not a legal guarantee. See how it works for stores on the ecommerce solutions page, test a single ad with the free GDPR ad checker, or start on the free plan.

This guide is general information, not legal advice.