Programmatic advertising platforms all promise the same thing: reach across the open web, connected TV, audio and apps from one login, with bidding handled by software. On a sales call they are hard to tell apart. In practice they differ a great deal in who can get an account, what inventory and data they favour, how much they charge on top of the media, and how much of the work lands on your team.
This guide is for marketers who have outgrown search and social and are deciding which platform to buy through. It covers what the platforms do, how the main ones differ, what a realistic all-in cost looks like, and how to run a trial that tells you something.
What programmatic advertising platforms actually are
The phrase covers several pieces of software that sit between an advertiser and a publisher. Buyers only log into one of them, but it helps to know the others exist because each takes a cut.
- Demand-side platform (DSP). The buyer's tool. You set budgets, audiences, bids and creative here, and the DSP bids on impressions for you. When people say "programmatic platform" they usually mean this.
- Supply-side platform (SSP). The publisher's tool. It packages a site's or app's ad space and offers it to DSPs.
- Ad exchange. The marketplace where the bid and the impression meet. Most exchanges are now part of an SSP.
- Data providers and DMPs or CDPs. Sources of audience segments, and the place your own customer data is prepared for targeting.
- Ad server and verification tools. The ad server delivers the creative and counts impressions independently. Verification vendors check viewability, fraud and brand safety.
The auction itself takes a fraction of a second and is covered in our guide to how real-time bidding works. For choosing a platform, the DSP is the decision that matters. It determines which exchanges you can reach, which data you can use, and what your reports look like.
The main types of DSP
There are dozens of DSPs. They fall into four groups, and knowing which group fits you narrows the list quickly.
Enterprise independents
The Trade Desk is the largest independent DSP, meaning it does not own the media it sells. That independence is its pitch: it has no reason to steer your budget toward its own inventory. It is strong in connected TV and audio, and it has pushed its own identity framework for targeting without third-party cookies. The trade-off is access. Direct seats come with spend commitments that put them out of reach for smaller advertisers, who usually buy through an agency or a reseller instead.
Walled-garden DSPs
Google's Display & Video 360 and Amazon DSP belong to companies that also own a great deal of media and data.
- Display & Video 360 is the programmatic buying tool in Google Marketing Platform. It is one of the main routes to buying YouTube programmatically and it connects closely with Google's ad server, which we cover in the Campaign Manager 360 guide. If your measurement already runs on Google's stack, this is the least effort.
- Amazon DSP lets you target using Amazon's shopping signals and buy across Amazon's own properties, including Prime Video and Twitch, as well as third-party sites. You do not need to sell on Amazon to use it. It is the obvious choice for consumer brands and worth a look for anyone buying streaming TV.
The catch with both is that the owner is also grading its own homework. Reporting on the inventory it owns comes from inside the same company that sold it to you.
Mid-market and self-serve DSPs
StackAdapt, Basis, Viant and Quantcast, among others, compete for advertisers who spend thousands or tens of thousands a month and not millions. They have lower minimums, friendlier interfaces and more hands-on support. Several have built specific strengths, such as B2B firmographic targeting or local and regional buying. Feature depth is thinner than the enterprise tools, but most teams at this budget never touch the advanced features anyway. If you want to operate the platform yourself, read our self-service advertising platform guide for what the day-to-day involves.
Specialist platforms
Some platforms do one thing. Criteo and AdRoll are built around retargeting and commerce. Simpli.fi focuses on local advertisers and small geographic areas. There are also platforms dedicated to connected TV, digital audio, digital out-of-home, and retail media networks run by large retailers. A specialist can outperform a general DSP in its own lane, but it will not cover the rest of your plan.
What programmatic buying really costs
The CPM you see in a sales deck is the media price. It is not what you will pay. Several fees stack on top, and some are easy to miss because they are deducted before the money reaches the auction.
- Platform fee. Most DSPs charge a percentage of media spend. Rates in the range of 10% to 20% are common, and they fall as your volume rises. Some charge a flat monthly fee instead.
- Data fees. Third-party audience segments are billed as an extra CPM, often between $0.50 and $3.00 depending on how specific the segment is. Your own first-party data is usually free to use.
- Verification and brand safety. Pre-bid filtering and measurement from a third-party vendor add a small CPM each.
- Supply-side fees. The SSP keeps a share of what you bid before paying the publisher. You never see this as a line item, but it reduces how much of your money buys actual media.
- Managed-service or agency fee. If someone else runs the campaigns, add their margin. Our article on choosing a programmatic advertising agency explains the fee models and how to keep them transparent.
Industry audits have shown how much this adds up to. The Association of National Advertisers' 2023 study of the programmatic supply chain estimated that only about 36 cents of each dollar entering a DSP reached a consumer as a viewable, valid ad on a quality site. The rest went to fees, non-viewable impressions, invalid traffic and low-quality "made for advertising" sites.
A worked example
Say a DSP quotes an average media CPM of $6.00 and you have $20,000 to spend.
- Media: $6.00
- Platform fee at 15% of media: $0.90
- Third-party audience segment: $1.50
- Verification: $0.15
- All-in CPM: $8.55
At $6.00 you would expect about 3.33 million impressions. At $8.55 you get about 2.34 million, which is 30% fewer. Nothing went wrong and nobody misled you. The quoted figure just left out everything except the media.
Do this arithmetic before comparing platforms, because a DSP with a higher platform fee and free built-in data can be cheaper than one with a low fee and expensive segments. Our CPM calculator will convert between budget, impressions and CPM so you can compare quotes on the same basis.
Minimum spends and who can get in
Access rules exclude more buyers than features do. Before you fall for a platform, find out whether it will take your budget.
- Enterprise DSPs generally expect large annual commitments for a direct contract. Below that, you reach them through an agency seat or an authorised reseller, which adds a margin.
- Amazon DSP offers self-service and managed-service options. The managed route has carried a minimum spend that varies by country, so ask your Amazon contact for the current figure.
- Mid-market DSPs often start in the low thousands of dollars a month, and a few have no formal minimum at all.
There is also a practical floor that has nothing to do with contracts. Programmatic bidding algorithms need conversions to learn from. If your budget produces only a handful of conversions a month, the platform has too little data to work with and you will be paying for guesswork. As a rough guide, budget enough to generate at least 30 to 50 conversions a month per campaign, or optimise toward an earlier action such as a product-page visit until volume builds.
If the numbers do not reach that level, it is reasonable to stay on search and social for now. Our overview of digital advertising platforms compares those options.
How to compare platforms
Ask every vendor the same questions and write the answers down side by side.
Inventory. Which exchanges and SSPs does the platform connect to, and does it have direct deals with the publishers and streaming services you care about? Ask about private marketplaces, which are invitation-only deals that usually carry better quality than the open auction. If connected TV matters to you, ask which apps you can actually buy and whether reporting shows the app or channel where each ad ran. Our guide to streaming TV ads covers what to expect there.
Data and identity. Third-party cookies are unreliable across much of the web, so the question is what the platform uses instead. Look for straightforward onboarding of your own customer lists, support for the common alternative identifiers, contextual targeting that reads page content, and for B2B, the ability to target by company or job role.
Transparency. Can you see a log of where every impression ran, down to the domain or app? Does the platform disclose its own fee and the supply-side fee? Does it support supply-path optimisation, which removes resellers that add cost without adding reach? A vendor that will not show placement-level reporting is asking for trust it has not earned.
Measurement. Check that the platform works with your ad server and analytics, supports third-party verification, and can pass conversion data back cleanly. Ask how it handles view-through conversions. A long view-through window makes almost any display campaign look profitable, so you want to control that setting yourself.
Workflow and support. Sit through a live demo of building a campaign, not a slide deck. Ask who answers when something breaks, how long creative approval takes, and whether there is an API or bulk editor if you run many campaigns.
Contract terms. Look for the commitment length, what happens if you underspend, and who owns the data and audiences you build. Month-to-month terms are worth paying slightly more for in the first year.
Common mistakes
Buying on CPM alone. The cheapest impressions are cheap for a reason. They tend to sit on cluttered pages, below the fold, or on sites built only to harvest ad revenue. Judge on cost per outcome and check viewability.
Leaving the open exchange unfiltered. Launching without an inclusion list, a blocklist or pre-bid brand-safety filtering sends budget to the long tail of low-quality sites. Start narrow and widen as the data supports it.
Trusting platform-reported conversions. Every platform claims credit generously. Compare its numbers with your own analytics and, when you can, run a holdout test where part of the audience sees no ads. The difference between the two groups is the real effect.
Signing an annual commitment first. A long contract before you have any data removes your ability to leave. Negotiate a trial period.
Sending the same creative everywhere. A banner resized for connected TV or audio does not work. Budget for format-specific creative from the start.
Run a pilot before you commit
A structured trial costs little and answers most of the questions a sales process cannot.
- Set one goal and one success metric. For example, qualified leads at or below a target cost. Work out that target from your margins first. The CAC calculator helps you find the acquisition cost your business can sustain.
- Shortlist two platforms from the group that fits your budget, and give each the same audience, creative, geography and budget.
- Run for six to eight weeks. Shorter tests end before the bidding algorithms have settled.
- Measure in your own analytics, with the same attribution rules for both platforms. Feed revenue and spend into the ROAS calculator so the comparison uses all-in cost, including fees.
- Review the placement reports. Look at where the money went as well as what it returned. A platform that performed slightly worse but spent on recognisable publishers may be the safer long-term choice.
- Decide and negotiate. Use the pilot results to ask for a lower platform fee or a shorter commitment.
Two platforms is enough. Testing four at once splits the budget so thinly that none of them gets a fair run.
FAQ
What is the difference between a DSP and an ad network?
An ad network buys inventory from publishers, bundles it and resells it to advertisers, usually without telling you exactly where your ads will run or what margin it kept. A DSP gives you direct access to auctions across many exchanges, with control over each bid and reporting on each placement. Many old ad networks now operate as DSPs, so ask whether you get placement-level reporting and a disclosed fee.
How much budget do I need for programmatic advertising?
For a mid-market self-serve DSP, a few thousand dollars a month is enough to start, provided it generates enough conversions for the algorithm to learn. Enterprise platforms expect far larger commitments or access through an agency. If your total paid budget is small, search and social will usually return more until you have an audience worth scaling.
Is Google Ads a programmatic advertising platform?
Partly. Google Ads buys display and video inventory through automated auctions, so the mechanics are programmatic. It is limited mostly to Google's own network, though. A full DSP such as Display & Video 360 reaches many more exchanges, supports private marketplace deals and gives finer control over frequency across publishers.
Which programmatic advertising platform is best for B2B?
There is no single answer, but look for account-based targeting, firmographic data partnerships and the ability to upload a target-account list. Several mid-market DSPs have built their product around B2B buyers. Whichever you choose, measure on pipeline and revenue, since B2B click and impression numbers say little about deal quality.