Tuesday, August 09, 2011 | 9:42 AM
In what we call "Search Ads Pause Studies," our group of researchers observed organic click volume in the absence of search ads. Then they built a statistical model to predict click volume for given levels of ad spend. This model generates estimates for the incremental clicks attributable to search ads or, in other words, the percentage of paid clicks that are not made up for by organic clicks when search ads are paused.
On average, the incremental ad clicks (IAC) percentage across verticals is 89%. This means that a full 89% of the traffic generated by search ads is not replaced by organic clicks when ads are paused. This number was consistently high across verticals. You can find a video on the study here. The full study can be found on research.google.com.