One theory that some search marketers hold is that purchasing Google AdWords does not make financial sense because the ads will cannibalize organic listings. The theory supposes that the two forces, AdWords and SEO, are killing each other, and it is a bad strategy to spend money on both at the same time.
As an experiment, Google "paused" search ads to measure the effect that such a cessation had on organic search result clicks. What the study found was that users did not suddenly start clicking the natural results in the absence of AdWords results.
Those findings prove wrong the notion that any significant increase in clicks on organic listings would result if marketers were to decrease spending on PPC ads, with Google deducing that 50% of the time ad clicks are incremental when there’s a corresponding natural listing in the top rank.
Pay-per-click is here to stay
In 2011, when Google claimed that 89% of the traffic generated by search ads is not replaced by organic clicks when ads are paused, it may have been a bit hard for the Internet marketing community to believe that statistic. After all, Google would say something like that to protect the reputation of AdWords, its main money spinner.
Cutting costs on advertising does not increase natural clicks
What the Google experiment tells Google advertisers is this: If you reduce your ad spending to zero, you can’t expect for 89% of those clicks that would have gone to your ads to now be redirected to your Web page results in the natural SERPs.
Also, a Google report a month later showed that, most of the time, paid ads and natural listings seldom appear on the same page together anyway.