I’ve read a few articles lately—mostly in and around the Transaction ID (TID) debate—that argue some version of the following point:
“Impression duplication is good for publishers because it makes them more money.”
On the surface, this sounds like a good argument – and in the short term it does. But, in my experience, there’s a nuanced story behind this statement and a strong argument that bid duplication is actually bad for everyone.
The Rational Behavior Behind Duplication
It’s absolutely true that impression duplication increases demand for a publisher.
Chris Kane has articulated this better than anyone: publishers are behaving rationally when they implement every SSP, reseller, format, and bid duplication feature or trick that can help them inflate their bid request volume.
In the short term, this strategy works. The first publisher to adopt a new duplication tactic—whether by adding another SSP, another reseller, or another format—sees a real lift in monetization. They’re taking demand from every other publisher. It’s the balloon-squeeze effect: push one side in, another side pops out.
But here’s the problem: the advantage is relative, not absolute. It doesn’t create new demand—it just redirects the demand that already exists.
The Balloon Squeeze
The first publisher to duplicate impressions sees a big bump. The second publisher to copy them gets almost the same benefit, but slightly less. The third, fourth, and fifth publishers each get a little less again. Eventually, once more than half the market is duplicating impressions, the first movers begin to see declines. The balloon has nowhere left to go.
At that point, the only way to maintain an advantage is to increase the level of duplication—add more resellers, more duplicative requests. It’s like a drug whose effects dull over time: to get the same high, you need a higher dose.
The Dystopian Market
When everyone duplicates, no one wins.
Once the market has become saturated with a specific duplication tactic, every publisher that uses that tactic ends up seeing roughly the same demand they had before the tactic was introduced—only now, the market is flooded with redundant requests which makes it harder for DSPs to do their job creating performance for advertisers.
Advertisers see worse performance.
Spend shifts back to walled gardens.
The open internet loses.
And the irony is that this dynamic hurts everyone, including the folks who build and maintain the duplication tech in the first place. SSPs and Publishers face rising infrastructure costs from pumping inflated impression volumes through the pipes. Those extra queries have real server cost—and real climate impact. And once the duplication tech exists, they have to keep maintaining it and building onto it. Whole teams of engineers and operators end up working just to preserve impression duplication tactics that no longer produce any benefit. Most SSP product leaders I know, bemoan the current state of the market (and in fact, here is Matt Sattel of OpenX last week on Marketcture discussing how duplication hurts them) – they have to spend precious engineering resources maintaining an inelegant system. They would rather use those resources on real, durable value-added product features.
Why the Sell Side Can’t Fix It Alone
It’s structurally impossible for any one publisher or SSP to stop impression duplication. The moment someone on the sell side turns off a duplicative pathway, their revenue drops. They become the “skinny part” of the balloon and their money shifts to other pathways.
This is why the problem won’t solve itself. As Chris Kane points out – the incentives are upside down.
The only way out is a market reset—a shift where everyone stops duplicating at once and returns to a clean model where impressions are accurately represented and described.
A Better Future for Everyone
If the industry can move toward transparent auctions without duplication — buyers will get better performance. Publishers will also win, because when advertisers get better performance, money comes out of the walled gardens and flows into the open internet.
The kicker here is – I believe that SSPs will also win. They will be free to focus on value-add activities: yield optimization, creative innovation, better user experiences vs. spending resources building and maintaining duplication tech that, at best, provides short term benefit.
In that world, buyers win. Publishers win. And everyone can stop wasting energy, engineering resources, and server costs on duplication and focus on building real market value that pulls spend out of walled gardens and helps grow the open internet.