A promotion is a time-limited offer of extra value attached to a product listing or an advertisement, submitted as structured data and displayed beside the price rather than folded into it. Money off, a percentage off, a free gift, free delivery, cash back: each is expressed through defined fields carrying a start time, an end time and conditions, so an advertising system can render the offer, check it and expire it without the advertiser rewriting the ad or changing the listed price.

The separation is the reason the construct exists. A retailer that discounts a jacket from 80 to 60 has changed its price, and every downstream system reading that feed sees the new figure. A retailer offering 20 off orders above 100, redeemable with a code, has left the jacket at 80 and layered a conditional incentive on top. The second arrangement preserves the reference price, targets a basket rather than an item, and can be switched off at a fixed hour. Ad copy could not carry those conditions, and a discount requiring a code cannot be inferred from a feed price, so platforms built a separate data structure for it. Submitting one costs nothing.

What the feed actually carries

Google's promotions data specification is the most detailed published description of the object. Six attributes are required. Promotion ID is a case-sensitive string of up to 50 characters linking the offer to products. Products eligible for promotion takes all products or specific products, the latter needing product filters or the ID mapped into the product source. Coupon code required takes no code or generic code, and a generic code demands a redemption code of up to 20 characters. Promotion title is capped at 60 characters. Effective dates use an ISO 8601 interval, two timestamps with time zone offsets separated by a forward slash, and no promotion may run beyond 183 days. Eligible channel marks the offer online, in store, or both. Destination is set separately and is a repeated field, so one offer can address Shopping ads, free listings and local inventory ads at once.

The commercial substance sits in a single optional attribute. Coupon value type accepts eighteen enumerated values, among them money off, percent off, buy M get N money off, free gift with value, free shipping two day, cash back and percentage cash back, and each dictates which further attributes become mandatory. Money off requires a monetary discount amount; buy M get N percent off requires a percentage, a minimum purchase quantity and a quantity eligible for the promotion. Two values exist only for United States sale events. Preconditions use minimum purchase amount and quantity; ceilings use maximum purchase quantity and maximum discount amount, which is how "10% off up to 100" is encoded. A redemption restriction enum covers subscribe and save, first order, email and text sign-up, a payment-method condition limited to India and Brazil, and a custom string.

Two limits shape planning. Up to 10 promotion IDs can map to one product, but ads and free listings display only one promotion per product, and accounts face a quota on active offers. Google reviews every promotion against programme policies and editorial requirements before display, and the landing page must match the submitted data. Display is confined to 13 countries.

The account-side object

Search advertising carries a parallel construct that never touches a product feed. In Google Ads it is the promotion asset, represented in the API as a promotion feed item with fields for occasion, discount modifier, promotion target, a percentage or monetary discount, an orders-over amount, a promotion code and start and end dates. An occasion, drawn from more than thirty holidays and retail events, constrains the redemption window to that occasion's date range. Assets attach at account, campaign or ad group level, the narrower overriding the broader. Microsoft Advertising implements the same idea as a promotion ad extension, storing percentages in micros, so 20% is written as 20000000.

Format restrictions apply where the offer meets a physical location. Local promotions attach through promotion assets, and Google's documentation states that QR code and barcode promotions serve only on Maps, not on Search, Shorts or in-stream video, a constraint restated when Waze inventory reached 41 further countries.

Origin and evolution

Google announced promotions for Google Shopping on 18 October 2012, a day after the vertical completed its transition to a paid model. More than 25 United States retailers were live at launch, among them 1-800-FLOWERS.com, OfficeMax, Tommy Hilfiger, Overstock, Guitar Center and Wayfair, and the same offers could be distributed through Google Offers and Google Maps on Android. Trade accounts of the launch date diverge: some vendor guides place the introduction in 2012 with the European rollout later, others date the feature to October 2014, which appears to describe wider availability rather than the original programme.

The search-side asset arrived later. Promotion extensions ran in beta from late 2016 and rolled out generally in November 2017, restricted at first to the redesigned AdWords interface. Google renamed all ad extensions to assets on 15 September 2022, a terminology change that left the fields untouched. Promotions reached free listings during 2020, after Shopping opened to unpaid results.

Recent additions have narrowed rather than broadened. A first-order discount condition reached Merchant Center in December 2024. Audience controls followed on 6 November 2025, letting merchants restrict offers to new customers or to specific regions, with an asymmetry that complicated planning: new-customer targeting served only Shopping ads, location targeting only organic listings. Regional promotions depend on region IDs, the same objects behind regional price overrides.

Why it matters for marketers

Promotional inventory is where large sums move without media budget. Amazon claimed shoppers saved more than 50 billion dollars on deals and coupons during 2025, a figure the company reports itself and no third party audits. Retail calendars are built around promotional windows, and inbound logistics is scheduled against them, as sellers found when Amazon set a 16 September stock cutoff for an event whose dates were unannounced and when Walmart published Black Friday and Cyber Monday dates months ahead.

The offer layer also decides which conditional prices appear at all. Google restricts loyalty pricing display to member discounts of at least 5% and at least 2 dollars against the regular or sale price, and prioritises an unconditional merchant promotion over member pricing when both apply. That ordering matters for retailers running membership schemes alongside sitewide offers, a group that grew when Google extended loyalty features to 14 countries and to AI Mode and Gemini on 25 March 2026. Sephora's United States business reported a 20% higher click-through rate on personalised annotations shown to members, a figure Google supplied at Think Week 2025.

Limitations and disputes

The reference price is the weak joint. European law removed most of the ambiguity: Article 6a of Directive 98/6/EC, inserted by the Omnibus Directive and applicable from 28 May 2022, requires any announced reduction to state the lowest price applied during at least the 30 days beforehand, and the Court of Justice held in Case C-330/23 that a percentage reduction must be calculated from that prior price, a rule examined in the treatment of second-hand discounts.

Marketplaces have reached similar conclusions commercially. Amazon tightened List Price and Typical Price validation with deadlines of 23 April and 18 May 2026, reclassifying discounts not advertised as promotions as ordinary sales for reference-price purposes and applying a 90-day rolling window before eligibility recovers. Hadia Arif, an Amazon advertising strategist, wrote that listings running permanent coupons showed 15 to 20% lower conversion once the coupon was stripped than listings with a clean static price. Persistent promotion erodes the baseline it depends on.

Effect sizes are poorly evidenced. Vendor and agency guides commonly cite click-through improvements of 5 to 10%, but the underlying studies come from parties selling feed management or advertising, and no independent measurement of promotion annotations has been published.

Disambiguation

Sale price is a product attribute. The discount is already inside the displayed price, available to everyone without a code, and generates strikethrough pricing. A promotion sits on top of whatever price is showing.

Price drop badges are generated by the platform from observed pricing history rather than declared by the merchant, which is why erratic pricing suppresses them.

Promotion mode is unrelated to shopper-facing offers. It is a Google Ads bidding setting, launched in beta in August 2026, scheduling a temporary change to return on ad spend tolerance and extra daily budget across a date range. Ginny Marvin, Ads Product Liaison at Google, set out the distinction from seasonality adjustments, which instead signal an expected conversion rate change.

Member pricing is conditional on loyalty enrolment and governed by a separate loyalty programme attribute, not the promotions source.

Recent developments

Management has moved to the Merchant API, whose promotions sub-API replaces the Content API endpoints with an accounts.promotions resource supporting insert, get and list. Marketplaces are meanwhile pricing the discount function directly: TikTok Shop charges enrolled sellers 3.5% of total store gross merchandise value for Smart Promotion, which distributes discounts algorithmically and attributes orders where one was redeemed, against the merchandise value platform reporting counts.

Agentic shopping poses the harder question. Google's Universal Cart, unveiled on 19 May 2026, tracks deals and applies codes inside Google's own surfaces, and the Universal Commerce Protocol publishes machine-readable merchant profiles assistants can read. Codes found and applied before any navigation remove the click that coupon and deal publishers monetise, and weaken the case for an annotation designed to catch a human eye. What a structured offer is for, when the reader is software, has not been settled.

Timeline

  • 17 October 2012: Google Shopping completes its transition to a paid listings model
  • 18 October 2012: Google announces promotions for Google Shopping with more than 25 United States retailers
  • 2014 to 2016: Merchant promotions become available in the United Kingdom, Germany, France, Australia and India
  • Late 2016: Promotion extensions enter beta in AdWords
  • November 2017: Promotion extensions roll out generally in the redesigned AdWords interface
  • 2020: Promotions begin appearing on free Shopping listings
  • 28 May 2022: Article 6a of Directive 98/6/EC becomes applicable across the European Union
  • 15 September 2022: Google renames ad extensions to assets
  • April 2024: The loyalty programme attribute enters the Merchant Center product data specification
  • 26 September 2024: The Court of Justice rules in Case C-330/23 on calculating announced reductions
  • December 2024: A first-order discount condition appears in Merchant Center promotions
  • 6 November 2025: Audience targeting arrives for Shopping promotions
  • 25 March 2026: Loyalty features expand to 14 countries and to AI Mode and Gemini
  • 23 April and 18 May 2026: Amazon List Price and Typical Price validation rules take effect
  • August 2026: Google Ads opens the promotion mode bidding beta

Summary

Who. Retailers and brands create promotions; feed management vendors and agencies submit them; Google, Amazon, Microsoft, TikTok Shop and Walmart define the fields, review the offers and decide which annotation displays. Consumer regulators, principally in the European Union, judge whether the saving claimed is real.

What. A time-bound offer of extra value expressed as structured data, carrying an identifier, a title, a validity interval, an eligible channel, a destination, a value type and a set of preconditions and limits, and shown alongside a listing rather than inside its price.

When. The construct dates to 18 October 2012 on Google Shopping, gained a search-side counterpart with promotion extensions in November 2017, was renamed to assets in September 2022, and has been narrowed by audience, loyalty and reference-price rules through 2025 and 2026.

Where. In Merchant Center promotions sources and the Merchant API, in Google Ads and Microsoft Advertising asset libraries, on Shopping ads, free listings, local inventory ads, Maps and AI surfaces, and inside marketplace tools at Amazon, Walmart and TikTok Shop.

Why. It lets an advertiser change what an offer says without changing what an item costs, which preserves reference prices, comparison data and campaign history. That same separation is what makes the reference price contestable, and it is the reason regulators and marketplaces spent 2022 to 2026 defining what a discount must be measured against.