Some of the ideas circulating in AdTech right now were questionable five years ago and are outright wrong today. The myths below come up regularly in conversations with buyers and publishers – and each is costing someone money.
This one has been announced so many times that many teams have quietly started treating it as settled. However, it isn’t.
Third-party cookies continue to function in Chrome, which accounts for around 65% of global browser traffic. Google revised its deprecation timeline repeatedly over five years, and in April 2025, confirmed it would not deprecate third-party cookies in Chrome. In October 2025, Google retired most Privacy Sandbox APIs and ended its push for a Chrome-led replacement for third-party cookies entirely. Firefox and Safari have blocked third-party cookies for years, so for those browsers, the signal was already gone.
Google’s Changing Plans
Third-Party Cookie Deprecation: Announced vs. Reality
Privacy Sandbox APIs retired by Google in October 2025. Third-party cookie deprecation not executed. Source: Google Privacy Sandbox announcements.
The problem with treating cookies as dead is that it leads to premature decisions. This includes, for example, abandoning cookie-based audience segments that still work on the majority of inventory, or adopting alternative identity solutions that add cost and complexity without a clear performance advantage.
What has genuinely changed is the signal environment. Chrome-based cookie signal remains available, but Firefox and Safari have been blocking third-party cookies for years, which already covers a meaningful share of any publisher’s audience.
Privacy regulations are tightening across markets independently of browser decisions. So, building a measurement and targeting approach that doesn’t depend entirely on third-party cookies is a reasonable long-term move. However, it doesn’t mean publishers should treat the deprecation as already complete and restructure everything around that assumption.
The practical question for any team is “what share of my current inventory still passes cookie signal, and what’s my plan for the share that doesn’t?”
For publishers, this one has a persistent appeal because it seems like straightforward arithmetic: If one ad unit generates X, four units generate 4X. However, this is wrong, and here’s why:
The more useful frame is revenue per session. A page with two well-placed, viewable units that loads in two seconds and keeps the user engaged for three minutes can generate more revenue than a page with eight units that drives the user away in thirty seconds. The units you didn’t show to someone who bounced are worth nothing.
The floor on this is ad quality. High ad density combined with low-quality or disruptive creatives accelerates user churn and attracts fewer brand advertisers, further compressing CPM. Publishers who have grown revenue by reducing ad count typically report the same result:
Fewer units with higher viewability attracted better advertiser demand and recovered the revenue lost from the removed units, sometimes with room to spare.
This myth has its roots in the early years of push as a channel, when parts of the ecosystem were generating opt-ins at scale through low-quality subscription networks with poor consent practices. However, later, reputable networks addressed those practices, and the category has changed substantially since then.
Push notifications are a direct channel to users who opted in to receive them. The opt-in is the key distinction: this is a message delivered only to those who agreed to receive messages from that source. That difference in consent matters for engagement potential.
What the “low quality” characterization usually reflects is not the format itself but how it is bought. Push traffic aggregated from low-CPC zones across broad GEOs, without vertical or behavioral filtering, will perform poorly. But the same is true of any format bought that way: display, native, and video traffic bought without segmentation also doesn’t show any good results.
Meanwhile, Push performs well in verticals where the product has broad appeal and the conversion action is simple: app installs, subscription offers, e-commerce, iGaming in regulated markets, finance lead generation. It is not so effective, though, in verticals requiring high consideration, long research cycles, or deep brand familiarity before conversion. So, the quality in this context is a targeting and offer-matching issue.
Teams that have written off push based on a test with the wrong offer, GEO, or optimization window might make decisions based on incomplete data. The format is worth a properly structured test before it is eliminated from the mix.
This was a reasonable observation in 2015. Demand-side platforms required significant minimum spends, dedicated trading desks, and technical integrations that were out of reach for smaller operations.
The infrastructure has changed:
The real barrier is data interpretation. A small buyer can quickly generate a large amount of performance data. However, the platform does not teach how to interpret it, separate signal from noise, or decide when to cut a campaign versus give it more time. Those skills come with experience or outside support.
Teams that have struggled with programmatic have usually hit the data interpretation problem. The tools are accessible, but making good decisions with the output they produce is where the learning curve sits in 2026.
CTR is a useful early signal but a poor optimization target. These are different things, and conflating them is one of the more reliable ways to spend a budget efficiently on traffic that does not convert.
A high CTR means users clicked. It says nothing about what happened after the click. A campaign with a 4% CTR and a 0.3% post-click conversion rate is underperforming a campaign with a 1% CTR and a 1.2% post-click conversion rate by a significant margin, and optimizing toward CTR would make the first campaign worse, not better.
There is also a selection effect. Creatives optimized purely for clicks tend to attract users who click reflexively on certain visual patterns, color combinations, or urgency framings – but not those who are genuinely interested in the offer. This produces traffic with high bounce rates, low time-on-site, and conversion rates that underperform even relative to lower-CTR campaigns with better intent alignment.
CTR is worth watching at the creative testing stage to understand which assets generate interest. It is also worth monitoring as a diagnostic signal when something has changed. However, it is not a performance metric for the whole ongoing campaign optimization. The post-click funnel (landing page engagement, conversion rate, cost per acquisition) is where campaign quality is actually measured.
The Math Behind the Myth
CTR-First vs. Conversion-First Optimization
| Metric | CTR-First | Conversion-First |
|---|---|---|
| CTR | 4% | 1% |
| Post-click CVR | 0.3% | 1.5% |
| Conversions per 10,000 impressions | 12 | 15 |
| Outcome | Fewer conversions despite higher CTR | 25% more conversions from the same inventory |
Figures are illustrative. CTR × CVR = effective conversion rate. Optimizing toward CTR without post-click data produces a misleading picture of campaign quality.
Yes, in Chrome, which holds around 65% of the global browser market share. Google revised its deprecation plans repeatedly, then, in April 2025, confirmed that it would not deprecate third-party cookies in Chrome. In October 2025, Google retired most Privacy Sandbox APIs. Firefox and Safari have blocked third-party cookies for years. The practical situation is fragmented: Chrome inventory passes the cookie signal, but a meaningful share of the audience uses browsers where it does not.
It can, and the mechanism is viewability and session duration. Fewer, better-placed units tend to score higher on viewability metrics, which attracts better advertiser demand at higher CPMs. If reduced ad density also keeps users on the page longer, total session-level monetization can recover or exceed what was lost by removing units.
The primary change was industry-level cleanup of subscription networks that were generating non-consented or low-intent opt-ins. Current push traffic from reputable networks is built on verifiable opt-ins. The format also matured in terms of creative and targeting tooling available to buyers. The “low quality” characterization applies more accurately to specific buying practices than to the format itself.
Platform access is no longer the barrier. Self-serve tools are available across the major networks with accessible minimums. The practical requirements are a testing budget large enough to generate statistically meaningful data, a clear definition of the conversion event being optimized, and the analytical capacity to read campaign reports and make decisions from them. The technology is accessible; the skill is in the data interpretation.
Because it is visible, immediate, and easy to compare across campaigns. Conversion data takes longer to accumulate and requires proper postback or pixel setup to track accurately. Teams that are tracking only top-of-funnel metrics (because the setup for deeper tracking was not done) end up optimizing on what is available rather than what is meaningful. CTR is not a bad signal; it is a signal that gets misused when post-click data is not in place.