Google’s own advertising-effectiveness research found that holding both a top ad position and a top organic position for the same query captures meaningful incremental clicks compared to holding either position alone, rather than the two simply cannibalizing each other’s clicks as many marketers initially assume. The commonly cited figure from that research, published some years ago now, found roughly half of the ad clicks in this scenario were incremental, meaning they wouldn’t have gone to the organic listing anyway if the ad weren’t there. That specific figure comes from a real, Google-conducted study, but it’s old enough that it should be treated as directionally informative rather than assumed to precisely describe current click behavior, since search behavior, SERP layout, and the competitive advertising landscape have all shifted since that research was published.
Why the intuitive cannibalization assumption is wrong
The natural assumption is that if your brand already holds the top organic spot for a query, running an ad above it mostly just redirects clicks that would have gone to the organic listing anyway toward the paid listing instead, meaning the ad spend is largely wasted since you’d have gotten those users regardless. Google’s own research specifically tested this assumption and found it doesn’t hold nearly as strongly as intuition suggests. A substantial share of the clicks going to the ad in this dual-position scenario are genuinely incremental, representing users who wouldn’t have clicked through to the organic result even though it was available, whether because they didn’t scroll past the ad, didn’t notice or trust the organic result as much in that moment, or simply clicked the first thing presented regardless of its paid or organic status.
Why incrementality is higher when organic position is weaker
The same body of research found that incrementality increases substantially as the organic ranking position for the same domain gets weaker. When the associated organic result ranks lower on the page, further down among positions two through four, the share of ad clicks that are incremental rises further, and when the organic result ranks below the first several positions entirely, an even larger share of ad clicks are incremental, since a weaker organic position on its own is much less likely to capture the click that the ad ultimately does capture. This makes intuitive sense: the cannibalization concern is strongest exactly when the organic result is already extremely well-positioned to capture the click on its own, and weakest when the organic listing is less likely to be seen or clicked regardless of whether an ad is present.
Hypothetically, consider a hypothetical brand we’ll call “Site L” running an ad on its own branded query where it also ranks first organically. If Site L’s organic position for that query slipped to position 3 during a redesign, hypothetically the incremental value of keeping the ad running would likely increase, not decrease, since the weaker organic position would be less able to capture the click on its own, making the paid placement more valuable precisely when the organic result is less dominant.
Why this matters for paid-search budget decisions
This research directly undercuts a common budget-cutting argument, the idea that once a brand ranks first organically for its own branded or high-intent queries, running paid ads on those same terms is largely redundant spend. If a meaningful share of ad clicks in that exact scenario are genuinely incremental rather than cannibalized, cutting paid spend on well-ranked terms risks losing real, measurable traffic and conversions that the organic listing alone wasn’t capturing, not simply eliminating a redundant duplicate of clicks that would have happened anyway.
Why the exact percentage shouldn’t be treated as a current, precise figure
It’s worth being explicit about the limits of relying on the specific historical number here. The underlying study is a real, Google-conducted piece of research, not a fabricated or industry-invented statistic, but it dates back a number of years, and search behavior, the prevalence and format of paid ad units, and the broader SERP landscape (including newer features that didn’t exist when that research was conducted) have all changed materially since then. Treating the specific historical percentage as an exact, current figure risks overstating precision that the passage of time has likely eroded, even though the underlying finding, meaningful incrementality exists and increases as organic position weakens, remains a reasonable and well-supported directional conclusion to rely on.
The practical implication
The defensible takeaway for a brand deciding whether to maintain paid spend on queries where it already ranks well organically is that incrementality is real and Google’s own research supports treating dual-position presence as capturing more total clicks than either position alone would, particularly where the organic position isn’t the single strongest possible ranking. Before making a significant budget decision based on this finding, it’s worth running the brand’s own incrementality test (a genuine ad-pause experiment against a comparable control period) rather than relying solely on now-dated third-party research to determine the exact percentage relevant to a specific account’s current query set and competitive conditions, since Google’s historical figure is a useful directional reference point, not a number that should be assumed to transfer precisely to any given brand’s present-day situation.
