DSP vs SSP vs Ad Exchange vs Ad Network: What Each One Does

The four names get used as if they meant the same thing. They don't. The difference decides who sets the price, who sees the data, and how many intermediaries take a cut before the money reaches the site that showed the ad.

DSP vs SSP vs ad exchange vs ad network at a glance

What a DSP does

A demand-side platform is software for buying. The advertiser sets targeting, budget and a bidding strategy, connects audience data, and the DSP looks at every impression the connected exchanges offer it. For each one it decides, in milliseconds, whether to bid and how much.

You get reach across many sources from one interface, and you bid per impression instead of per placement. The cost is complexity: someone has to build audiences, set frequency caps and write brand safety rules, and most DSPs charge a fee on top of media spend. So DSPs end up with agencies and in-house teams that have steady budgets, not with a buyer testing an offer on a few hundred dollars.

What an SSP does

A supply-side platform mirrors the DSP from the publisher's side. It takes the publisher's ad slots, shows them to as many buyers as it can and tries to get the best price for each impression. It has two main levers: floor prices, the minimum the publisher will accept, and competition. The more demand sources bid on the same impression, the higher the clearing price tends to go.

Publishers usually pay an SSP a share of revenue. Many SSPs now run their own exchange too, which is one reason the terms blur. Header bidding belongs on this side of the chain as well: it lets several SSPs and exchanges bid on the same impression before the ad server decides. We cover it separately in the future of header bidding.

What an ad exchange is

An ad exchange is the marketplace. It receives a bid request from the supply side describing an impression (page, device, location, ad size), passes it to connected buyers, collects their bids and declares a winner. Most of this traffic follows OpenRTB, the protocol maintained by the IAB Tech Lab, so any DSP can talk to any SSP without a custom integration.

Few advertisers or publishers deal with an exchange directly any more. They reach it through a DSP or an SSP, and several large platforms bundle all three. Google Ad Manager, for example, combines an ad server, an SSP and the AdX exchange in one product.

How one impression moves through the chain

1. A visitor opens a page with an ad slot.
2. The publisher's SSP builds a bid request with what it knows about the impression and sends it to exchanges and buyers.
3. Interested DSPs reply with bids, usually within about 100 milliseconds.
4. The exchange picks the winning bid and, depending on the auction type, sets the price.
5. The winning DSP's ad is served, and both sides record the impression.

All of this happens while the page loads, which is why it is called real-time bidding.

Ad network vs ad exchange

An ad exchange is neutral ground. It owns no inventory; it runs the auction and takes a fee. An ad network is a business that sits between publishers and advertisers and sells access to its pool of traffic. It decides how that inventory is packaged, sets the prices or runs its own auction, and usually adds targeting, moderation and fraud filtering on top.

The line has moved, though. Many networks now buy and sell through RTB as well. Youtarget, for instance, is an ad network where advertisers buy traffic themselves, and it also connects to other platforms over OpenRTB 2.5: DSPs can buy its inventory, and it can take inventory from SSPs. What still differs is who you deal with. With a network you buy from one counterparty and get its pricing and its filters. With an exchange, through a DSP, you put the same pieces together yourself.

Which one do you need?

If you test offers or run performance campaigns on a limited budget, a self-serve ad network is the shortest path. You pick the format, the country and the bid, and you pay per click or per thousand impressions without signing a DSP contract. On Youtarget the minimum deposit is $50.

If you run brand campaigns with your own audience data and a monthly budget big enough to justify the setup, a DSP gives you impression-level control across many exchanges.

A small or mid-size publisher is usually better served by an ad network: one tag, one dashboard, one payout. Here is how publishers monetize with Youtarget. A large publisher with direct sales and steady traffic will want an SSP with header bidding, so that several buyers compete for every impression.

Where the money goes

Every link in the chain takes a share, and the shares add up. The most quoted measurement is the programmatic supply chain study by ISBA and PwC. In its first edition, published in 2020, 51% of the advertiser spend it could trace reached publishers, and 15% could not be attributed to any participant at all. The second edition, with fieldwork in September and October 2022 and top-line results in January 2023, found 65% reaching publishers and the unattributed share down to 3%.

Both editions could only follow impressions that matched between the buyer's and the seller's records, 12% in the first study and 58% in the second, so the figures are not a universal rate. They do explain why advertisers keep asking how many hops sit between them and the page.

A shorter chain isn't automatically cheaper, but with fewer intermediaries it is easier to see what you pay for. The same questions apply to a network: what data you get per placement, how traffic is filtered and how the price is formed.