Looks to me as an effort to make any user visiting google.com to not actually leave google.com FOREVER.
Users will get portal-ed to a result page (with the browser's url bar showing foo.com, instead of google.com), but the user will be tracked the entire time from google, since they would be still on google.com.
Users will get portal-ed to a result page (with the browser's url bar showing foo.com, instead of google.com), but the user will be tracked the entire time from google, since they would be still on google.com.