When you Google something, if you happen to introduce a typo in your search term, you get the “Showing results for search term”
For example, let’s search for the word “results” with a missing “u” : “reslts“. You can check the output here. You will get something like the image below.
What happens when you click in the “Showing results for results“? Well you get “exactly” the same set of results:
Some results have switched order of appearance though. The switches appear in 7th, 8th position that’s quite negligible isn’t it?
“Showing results for …”‘s link is useless
If we end up with exactly the same result, why is the request sent two times? I don’t know the percentage of people clicking in the link… But If Google shows the link, it means, that you should click on it to see some sort of search refinement.
Even though there is some refinement (20 more personal results, you can check that in the two images: the first has 150 personal results, and the second 170), it does not seem to be done in the first page. So this refinement is probably useless.
Bottom line is: Google is in the search business, so it may have some interest in people clicking on a link even if they see the same results twice. They may charge some additional AdSense or AdWords impressions.