As you may remember, I’ve been running a little AdSense experiment on this site. Here’s a brief summary for new readers:
The core motivation for the experiment was to test the prevalent assumption that people coming from search engines are the ones most likely to click on ads. To this end, I used a little piece of JS that would present different ads to people based on how they arrived on this site – either directly, from a search engine, from another kind of external site, or from a different page on the same site. All the ads were visually identical but were tracked separately.
The visitor segmentation script has been running uninterrupted for more than five months, allowing me to collect CTR and CPM data on more than 10 000 AdSense clicks. Overall, the trends look stable enough that running it for a while longer probably wouldn’t change the results. So now is a good time to post one final summary and declare the experiment concluded.
Internal Traffic Wins
At least on paper, it does. Out of all possible traffic sources, internal traffic – i.e. people who browse more than one page into the site – has the highest click-through rate and the highest eCPM. However, it also accounts for the least number of ad impressions. In a nutshell, internal traffic is valuable but rare.
Conversely, search engine traffic comes third in terms of CTR and eCPM, but brings the most money due to a high number of impressions.
The full results are below. To comply with AdSense ToS which prevent me from displaying the actual numbers, the results have been normalized to display the relative CTR and eCPM of various traffic sources.
The above results are based on:
- > 18 000 clicks.
- > 400 000 impressions (73% search engine traffic).
All data was collected during an uninterrupted 168 day period (2010.03.09 – 2010.08.24) on this very same site. Results may be different for other sites.Related posts :