Google's sitelinks are often the object of amusing discussions in the established SEO-forums. No one really possesses any substantiated knowledge on this issue – hence you get the most abstruse interpretations and ideas. To complete this confusion, here some of my own ideas on this subject. Sitelinks are those links in the Google SERPs that can be found below the first hit from time to time, which will show 4 deeplinks including the title, shown here in the highlighted part:


How these sitelinks are generated was published through one of Google's patents at the end of last year: the patent states that pageviews are logged through a toolbar – in this case obviously the Google-toolbar. Seeing that every PageRank-query is accompanied by an access to the Googleserver with the current URL, Google should be in possession of a database that is broad and diversified enough. Besides the actual pageview there are other informations that are saved and assessed, informations like the time spend on the site, which indicates how interesting or important a site is. It is very interesting that Google is basing this solely on the users behavior – this could provide a lift to the rumors which view the user behavior as a factor for the “normal” SERPs. Admittedly this only explains which sitelinks are chosen and displayed.

Another interesting question is when these sitelinks are displayed below the first hit – and only there – at all. Sadly the patent does not go as far as answering this, which forces us to use deliberations and observations. I want to add a “feature” of the Google-SERPs into the observations that I believe the public only has a limited knowledge of: prefetch. In their Browser, Mozilla implemented the possibility to load linked sites in the background so that they are at your disposal immediately after you click the corresponding link. Google is using this possibility to mark the first result in a part of its SERPs accordingly. An evaluation of 10.000 random SERPs has shows that a little more than 18 percent of the first results had the sitelinks and at least more than 37 percent were marked with this prefetch-attribute. In this context it is important to note that, without exceptions, all pages that had sitelinks were marked with prefetch. If we follow the train of though that the prefetch-attribute is pointing to an especially high clickrate in comparison to the other results, we could rate it as a preliminary-stage to the displaying of the sitelinks. Once we add other factors to this high clickrate – ”authority” or a large portion of links for the keyword, just to name two possibilities – we will see the sitelinks that are additionally won through the toolbar.