 Search engine optimization experts consider sitelinks to be an important measure of how "trusted" a site is, and accordingly have attempted to deduce what causes them to appear.These efforts have included looking at Google patents.According to these patents, sitelinks are derived from user behavior, in particular, the number of times a page has been accessed, the amount of time spent on the page, and from the content of the page itself—whether the page contains commercial transactions, etc.