How Ads Influence Organic Click-Through Rate On Google
Contributor Philip Petrescu presents the results of a study on how presence and type of ads on search engine results pages influence click-through rate (CTR).
With Google reporting, quarter after quarter, the increase of paid clicks, it is natural to be asking ourselves how many clicks are left for the organic listings. In a recent post, WordStream founder Larry Kim called it a “zero sum game.”
“Clicks on the search results page are basically a zero sum game. If there’s an increase in CTR for one part of the SERP, some other part is losing that click. There must be a decrease in CTR elsewhere. And that includes the ads.”
Since millions of sites depend upon Google for attracting potential customers, an ascending trend for the click-through rate (CTR) on ads can have a huge impact to online business as a whole.
In a recent study I presented at SMX East 2014, we investigated how ads (among a number of other factors) influence organic CTR and users’ search behaviour, attempting to bring to light the distribution of clicks between paid and organic.
The study is based on client data extracted from Google Webmaster Tools for the month of July from a total of 465,000 keywords across 5,000 websites. To protect our clients, the actual keywords have been anonymized in the data set.
While client businesses varied, they may belong to certain industries that differ from the industry you are in. Therefore, the results may not be the same for every business.
We matched the entire set of keywords from Google Webmaster Tools with the ones we track for each client in AWR Cloud. This way, we were able to get more information about the features included in the search engine results page (SERP), such as whether there were ads, the number of ads and their position, and if any Universal features were included in the search results.
Is Organic Click-Through Rate Altered By Ads?
We found that on average, the presence of ads on a search results page caused the organic CTR of the first position to drop by 30% — from 25.7% organic CTR in the absence of ads to 17.9% CTR when ads are displayed.
So, if you were counting on a 30% or more CTR for a top ranking in your performance calculations, think again. With most search queries displaying ads, the odds are that the real CTR you will have is much lower.
But, as we go further down the page, the impact of ads over organic CTR fades away. Below-the-fold listings (websites ranking from 6 to 10) are actually amassing a higher organic CTR when ads are displayed (2.99%) than without ads (2.24%).
“Ads can cut the clickthrough rate on the first result nearly in half, which is huge, while other positions are far less impacted.”
Do All Types Of Ads Have The Same Influence On Organic CTR?
After breaking down all search result pages by the type of ad displayed, we found that ad location is a highly important factor that influences organic CTR.
We set apart the pages with ads listed at the top of the page — those with ads listed at the right of the page and those with ads at the bottom.
A few notes on the methodology behind this process are worth being made:
- The pages selected with ads at the top may also have ads on the right side or at the bottom
- For those marked as “Right side ads,” we made sure there were no ads at the top, but they may have ads at the bottom
- The pages with ads at the bottom were selected to have no ads at the top or on the right side
As expected, ads at the top of results page seem to hurt organic CTR the most: 34.2% drop in CTR for the first organic listing and an average drop of 20.3% for the first page.
However, the impact of ads at the top of the page on the rest of the SERP is small in contrast to the first position.
The influence of both right side and bottom of the page ads is basically following the same pattern as the influence of top page ads — negative influence for the first position CTR and no or positive influence for the rest of the SERP, although on a different scale.
Organic CTR for the first position in search results drops by 20.6% when ads appear at the right side of the page, and by 10.7% when ads are displayed at the bottom of the page.
While the first organic listing seems to be negatively affected by all types of ads, the smaller impact of ads on the rest of the SERP is somewhat reassuring.
Compared to the first position, the organic CTR of the website listed second in search results increases by 64.3% when ads appear at the right side of the page, and by 24.1% when ads are displayed at the bottom of the page.
When ads appear at the top of the page, the first page of search results amasses 39.9% of organic clicks. When the ads appear only on the right side, the CTR increases substantially to 64%. The highest organic CTR (57.9%), is found when ads appear only at the bottom of the page.
Does The Number Of Ads Displayed At The Top Of The Results Page Have Any Influence On Organic CTR?
Looking further into the pages with top ads displayed, we found that the more ads are listed at the top of the page, the bigger the impact on organic CTR for the first position. With only one ad displayed, CTR for the first organic listing actually increases with 13.2%, while two and three ads determine the CTR to drop by 43.7% and 63.6%, respectively.
“I’d guess seeing just one ad with the yellow ad symbol may make the organic result seem more natural and trustworthy, and would therefore lift CTR above that of results showing no ads, while the addition of a further one or two ads reduces this effect by driving organic results down the page, or forcing users to scroll and see other results.”
“Certain search results, show an ad and an answer box before the organic results. One example is when you search for ‘dropbox max file size.’ The answer box that shows up could be a possible explanation for this anomaly.”
Surprisingly though, regardless of the number of ads displayed at the top of the page, their impact is always positive for the organic CTR of below-the-fold listings: 44.6% increase in CTR for one Top Ad, 34.8% increase for two Top Ads and only 6.7% increase for three Top Ads.
Thus, first page of results accounts for 56.8% of clicks with one Top Ad displayed, 41.5% of clicks with two Top Ads displayed and 29.1% when three Top Ads appear.
To summarize, here is the table of values illustrating the impact of ads on organic CTR for the first page of results and the all-time-craved first organic listing:
|1st Position CTR||CTR Change (%)||1st Page CTR||CTR Change (%)|
|With Top Ads||16.94||-34.19||39.9||-20.34|
|With Right Side Ads||20.44||-20.59||64.03||+27.83|
|With Bottom Ads||22.98||-10.72||57.88||+15.55|
|With 1 Top Ad||29.14||+13.21||56.8||+13.4|
|With 2 Top Ads||14.5||-43.67||41.54||-17.07|
|With 3 Top Ads||9.36||-63.64||29.13||-41.84|
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