Reclaiming the margin: why high-volume iGaming publishers are building their own ad networks

The biggest names in iGaming media get hundreds of millions monthly visits, yet only half of what advertisers spend on their inventory lands in their pocket. As a response to this challenge, the sector’s publishers are pulling premium inventory out of the open auction and selling it themselves.

Picture a sports-content site generating tens of millions of visits a month. An advertiser invests a dollar to put a message in front of that audience. How much of that dollar actually reaches the publisher?

If the inventory sells through the open programmatic auction, the answer is about 51 cents.

The landmark ISBA and PwC programmatic supply chain study, the most forensic audit the industry has produced, found that only around half of advertiser spend reaches the publisher — and it examined the most premium end of the market, so the long tail is likely worse.

The publishers with the most at stake here are not small. iGaming media has consolidated into a handful of high-traffic groups: sports and casino content networks, odds and scores portals, tipster and streaming destinations. Better Collective, the listed group behind Action Network and VegasInsider, reports roughly 450 million monthly visits across its brands and around $390m in 2024 revenue. A real share of money like that comes from display inventory sold to gambling advertisers, and that is precisely the inventory the ad tech taxes hardest.

So the question every high-volume publisher should be asking is a short one: who keeps the other half?

Where does the other half of the publisher’s revenue go?

Most of the leak happens on the way to the publisher — on the sell side, where the publisher has the least visibility.

If we take a closer look at ISBA and PwC report, the supply-side platform took around 14% of publisher revenue in the study data, noticeably more than the 12% their own contracts specified. On top of that emerge exchange-bidding fees of about 5% of publisher revenue that some participants did not know they were paying. Then comes the part nobody could explain: an “unknown delta” of 15% of advertiser spend, roughly a third of total supply-chain costs, that could not be attributed to any party in a supply chain every participant had agreed to disclose.

Where the inventory is sold matters too. In the open marketplace, only 49% of advertiser spend reached the publisher, against 54% in private marketplaces. The blunt open auction is the most expensive way a publisher can sell.

None of this has quietly fixed itself in the years since. The ANA’s 2024 programmatic benchmark found that of every $1,000 entering a demand-side platform, just $439 reached the publisher. That was up from $360 the year before. Years of transparency initiatives have shifted the number, but they did not close the gap to make it fair.

Why the open auction punishes iGaming hardest

Every publisher loses margin to the chain. Gambling media loses more, for three reasons.

The first is compliance. Gambling is among the most restricted categories on the open web. Google limits gambling advertising to a shortlist of licensed markets and keeps tightening the rules, and Meta layered in licensing and verification requirements for real-money gaming in 2025. Some (though not all) DSPs and SSPs apply category blocks that cannot distinguish a licensed operator in a regulated market from an unlicensed one.

The publisher ends up with rejected creatives, throttled delivery, and premium inventory backfilled by low-CPM remnant because the good gambling demand cannot transact cleanly.

The second is the direct-deal premium. Gambling brands do not want a banner lost in an auction. They want sponsorships, native integrations, branded odds widgets, custom skins at placements that are negotiated and that therefore may command controllably higher prices. Selling directly, the publisher keeps the lion’s share of their revenue. Routed through a third party, a slice disappears for a service the publisher could run autonomously.

The third is that the chain can turn on you. When the demand-side platform MediaMath went bankrupt in 2023, several SSPs clawed back money from publishers to cover a debt those publishers had nothing to do with — billing the seller for a meal the buyer skipped, as Forrester described it. As a publisher, you may carry the unknown risks of a supply chain whose economics you don’t control.

Taking the ad revenue ownership back

The move away from that exposure is not new at all. Publishers have been cutting on their sell-side stack for years. The largest US publishers cut the programmatic sell-side vendors they used by about a quarter as far back as 2018, and Forrester has framed the bankruptcy fallout as a pivoting point getting direct deals back in the spotlight, because they limit exposure to clawbacks and let publishers price their own audience.

The logical solution here is to own software that does the selling: the ad server.

An ad server is the publisher-side engine for direct media buying. It matches a specific ad to a specific placement, with no auction and no intermediary on the way. The publisher effectively becomes the ad network selling sponsorships and private deals under its own brand.

What’s more, setting up your own network keeps first-party audience data derived from registered users private. You keep the declared team and sport interests that are so valuable for targeting inside your own walls, rather than broadcasting it into the open bidstream.

How about the revenue share? An ad server charges a flat platform fee, not a percentage of every transaction. On a few thousand dollars a month that distinction is trivial. On a site selling millions in direct deals, the gap between a fixed fee and a chain that keeps half the money is surreal. Epom Ad Server, for example, has a simple fixed monthly pricing and includes an SSP module, so a publisher can sell premium inventory directly and let programmatic backfill the rest.

This is not a call to switch programmatic off. Open-auction demand is still the right tool for filling unsold impressions at scale, and most publishers keep it running underneath their direct business. The shift is narrower and sharper: stop letting the open auction price and tax your best inventory, and take ownership of the direct relationships the auction was never built to serve.

Who keeps the other half now

The high-volume publisher’s problem was never traffic, and never demand. It was handing both to a chain that priced the inventory, took its cut, and passed back roughly half — on the most sought-after audience in digital advertising. A private ad network does not create a new revenue stream but rather stops the leakage of the existing one.

For an iGaming site doing hundreds of millions of visits, the answer to “who keeps the other half” is finally starting to change. Increasingly, it is the publisher.

Serhii Shchelkov is an adtech expert specializing in publisher monetization infrastructure, programmatic operations, and ad server strategy. He works with Epom Ad Server, a white-label ad serving platform built for publishers, networks, and agencies operating at scale.

TNG – Latest News & Reviews