Programmatic advertising: how it works, display and affiliate marketing

What is display advertising?

Display advertising covers the visual ads shown on websites, apps and video platforms. It takes several forms: banners, videos, native formats, audio. It differs from search, where the ad answers a query.

In France, video now dominates display. It accounts for about 60% of display revenue in 2025, and the share of classic banners is falling.

What are the display formats?

• the banner, static or animated, placed within the page;
• instream video, played before, during or after video content;
• outstream video, which starts within an article or between two paragraphs;
• the native format, which takes on the look of the site’s content (recommendation widgets, sponsored articles);
• audio, in podcasts, web radio and music streaming platforms.

Display serves three purposes. It builds brand awareness and keeps an offer top of mind with a chosen audience. It also lets you reach visitors again who have not bought yet. It is most often paid on a CPM basis, that is, per thousand impressions.

What is programmatic advertising?

According to the CNIL (the French data protection authority), programmatic advertising makes it possible to plan the automatic purchase of inventory items. This purchase follows predefined criteria: price, audience characteristics, geolocation. The most widespread type is the real-time auction, or RTB. Source: the CNIL definition (in French), accessed on September 24, 2026.

Exchanges between platforms follow an open standard, OpenRTB, published by the IAB Tech Lab. It defines how an impression is put up for auction. It also sets the format of bid requests and bid responses between buyers and sellers. It covers display, video, audio and native, according to the documentation of the OpenRTB standard (accessed on September 24, 2026).

What is the difference between display and programmatic?

Display refers to a type of advertising: what the user sees on the screen. Programmatic refers to a buying method: the way the space is bought. The two combine. Programmatic display is display bought automatically, impression by impression. Display can also be bought directly from a publisher.

Question	Display	Programmatic
What is it?	A type of advertising: banner, video, native, audio	An automated way of buying ad space
What question does it answer?	What do we show the user?	How do we buy the impression?
Alternative	Search, social, affiliate	Direct or negotiated buying from the publisher

Programmatic already dominates video display buying: 76% of its revenue in France in 2025. It accounts for 51% of classic display revenue, according to the same Observatoire de l’e-pub.

How does a programmatic auction work?

Everything happens while the page loads, in a fraction of a second:

1. A user opens a page that contains an ad slot.
2. The publisher’s platform (SSP) sends a bid request. It describes the slot, the context and, if consent allows, the user.
3. The buyers’ platforms (DSPs) assess the impression against each campaign’s rules and send a bid.
4. The auction picks a winner, whose ad is displayed.
5. The display is measured: impression, viewability, click, any conversion.

Fictional example: a running shoe brand targets readers of sports websites in the Paris region (Île-de-France). Its DSP bids on these sites’ impressions, with a maximum price set in advance. A reader opens an article about the marathon and sees the brand’s video. The advertiser negotiated nothing with the site: it all happened during the auction.

Player	Role
Advertiser or agency	Defines the target, the budget, the buying rules and the creatives
DSP (Demand-Side Platform)	Buying platform: assesses each impression and bids for the advertiser
SSP (Supply-Side Platform)	Selling platform: puts the publisher’s impressions up for auction
Ad exchange	Marketplace where supply and demand meet
Publisher	Website or app that sells its ad space
Data tools	Audience segments, the advertiser’s first-party data (CRM)

What are the buying methods?

Buying method	Principle	Benefit
Open auction (open RTB)	Any buyer can bid on the inventory	Volume, low prices, quality control needs strengthening
Private deal (PMP)	Auction reserved for buyers invited by the publisher	Chosen sites, better quality
Programmatic guaranteed	Volume and price set in advance, delivered automatically	Predictability, premium inventory
Direct deal	Direct negotiation with the publisher, outside programmatic	Special operations, custom formats

Google Ads also gives access to display, through its Display and Performance Max campaigns, without going through a DSP. It is often the entry point for small advertisers. See Google Ads campaigns and our Performance Max page.

How do you launch a first programmatic advertising campaign?

1. Set the objective: awareness measured in viewable impressions, or conversions measured after a click.
2. Choose the access route: a Display campaign in Google Ads, a self-service DSP or a specialist agency.
3. Define the audience: segments, first-party data, topics, sites targeted or excluded.
4. Prepare the creatives: several sizes and formats, with a video version if possible.
5. Launch and check: review the placements from the first week, then adjust bids and exclusions.

How do you avoid fraud and invisible impressions?

An impression bought is not an ad seen. Three checks limit the waste.

Measured viewability

The Media Rating Council (MRC) sets the viewability standards. A display ad is viewable if at least 50% of its area appears on screen for at least one second. For a video, 50% of the area must be visible for at least two seconds of playback. For very large formats, the threshold drops to 30% of the area.

Source: Google Ads Help on Active View, accessed on September 26, 2026. Compare your campaigns on cost per thousand viewable impressions, not just on raw CPM.

Authorised sellers: ads.txt

The ads.txt file is an IAB Tech Lab standard. It lets a publisher declare publicly which companies may sell its inventory. It thus makes it harder to resell counterfeit inventory. The app-ads.txt file extends the principle to apps, and sellers.json documents the chain of sellers.

Source: the IAB Tech Lab’s ads.txt documentation, accessed on September 24, 2026. Require your DSP to buy only from declared sellers.

Brand safety

Three tools protect the brand’s image. Exclusion lists rule out sites, apps or topics. Inclusion lists restrict sensitive campaigns to chosen sites. Regular review of placement reports catches the rest. Together, they prevent an ad from appearing next to content that damages the brand. The subject ties in with branding work.

How do you do retargeting without wearing people out?

Retargeting shows ads to people who have already visited your website or used your app. It is often the first use of display for an online store. The audience has, after all, already shown interest.

• cap the exposure frequency per person and per day;
• exclude recent buyers, unless there is a relevant complementary offer;
• segment by intent: product page viewed, abandoned cart, simple visit;
• set a retargeting window consistent with your purchase cycle.

Retargeting relies on trackers. According to the CNIL, they require consent given through a clear affirmative act. Refusing must be as easy as accepting. Source: the CNIL guidelines (in French) of September 29, 2020. Retargetable audiences are therefore smaller than your actual traffic.

First-party data gains value in this context: customers, subscribers, accounts, collected with consent. It lets you target or exclude without depending on third-party cookies. Its quality is built in the CRM. Retargeting on social networks is covered in our social ads guide.

What is affiliate marketing?

Affiliate marketing pays partners, called affiliates or publishers, for the sales or leads they generate. The advertiser pays only for the result: a commission per sale (CPA) or per lead (CPL). Affiliates include cashback sites, promo code sites, comparison sites, content sites, creators and newsletters.

The relationship often goes through an affiliate platform. It recruits affiliates, tracks sales and pays commissions. The Observatoire de l’e-pub names, for example, Awin, CJ Affiliate, Effinity, Kwanko, Rakuten, TimeOne and Tradedoubler.

Three points call for vigilance:

• attribution: a promo code site can capture, on the last click, a sale that was already won. Define which affiliates are paid, and in which cases;
• affiliate quality: vet each partner. Forbid them from bidding on your brand in SEA if that is your policy;
• links: Google asks for paid links to be marked with the rel="sponsored" attribute. Source: Google Search Central, accessed on September 26, 2026.

This last point separates affiliate marketing from link building: a paid link must not pass on popularity. See our page on backlinks.

How do you measure a display or programmatic campaign?

Each metric answers a specific question. The table also shows its limits.

Metric	What it measures	Watch point
CPM	Cost per thousand impressions	Compare with viewable CPM, which is more accurate
Viewability rate	Share of impressions actually viewable (MRC standard)	A low CPM often hides low viewability
Click-through rate	Clicks divided by impressions	Low by nature in display; a poor indicator of awareness
Post-click conversions	Purchases or leads after a click	The most reliable metric for performance
Post-view conversions	Purchases after a simple exposure	Read with caution: the purchase might have happened without the ad
Frequency	Average number of exposures per person	Beyond a threshold, the ad wears people out

To measure the real effect of a campaign, nothing replaces a test. You compare the sales of an exposed group with those of an unexposed control group. The basics of conversion tracking are set out in our web analytics pillar page. If traffic arrives but converts poorly, work on the landing page with CRO.

Display, programmatic or affiliate: which should you choose?

Lever	Main objective	Payment model	Best when
Display via Google Ads	Awareness, remarketing	CPM or CPC	Small budget, need for simplicity
Programmatic via DSP	Awareness, precise audiences, video	CPM	Sufficient media budget, need to control the sites
Retargeting	Converting visitors	CPM or CPC	Existing qualified traffic, consent collected
Affiliate	Sales, leads	Commission on results	E-commerce or an offer with a clear order value

For a brand that is starting out, the logical order is often as follows. First reliable measurement, then retargeting on existing traffic. Next, display or programmatic prospecting, once the offer and the creatives have proven themselves. Affiliate marketing can be launched in parallel if the business lends itself to it.

In every case, programmatic advertising requires regular monitoring of placements and results. It automates the buying, not the judgement.