Yesterday I posted a video showing a "prefetch" hit coming from the Google SERPs. The bad news is that this turns out to be nothing new; I thought it may have been related to the recent page previews feature - It wasn't.
The good news is that there's an opportunity here, which I don't think has been discussed before.
To summarize: When you use the integrated search box in Firefox (top right) to search Google, Google will sometimes use a rel=prefetch attribute on the first result link. This causes Firefox to automatically download the HTML source code of the first result page. Along with the request to download the page, the referrer string is sent. This is great, because we have a hit to our server without the visitor ever clicking on our result.
So, what is the opportunity and how can we take advantage of it?
Simple. Because we have a hit directly from a Google SERP (along with the referrer string), we can identify searches where our site is ranking. If we don't get the click, then we know we have a problem.
So, let's go through this quickly so we can all get back to work.
In the Apache HTTP server, tell the server that you want to track only prefetch hits to a separate log file:
SetEnvIf X-moz prefetch Prefetch_Request #Set a variable when prefetch CustomLog /path/to/prefetch_log combined env=Prefetch_Request #Log the request if prefetch
Then restart the server. This will log any requests that come to the server with an X-mox: prefetch header to the /path/to/prefetch_log log file.
You can look through the data in this log file to determine where you're showing up in SERPs. If you compare this data to your normal log file, you will be able to identify where you don't get the clicks from the Google SERP.
What you do with this information is up you. I know what I would do - optimize the title and meta description/snippet to maximize the click-through rate.