After years of going ad-free, del.icio.us has quietly started to integrate contextual search ads from Yahoo Search Marketing. For now, ads only show up when users search the entire index of bookmarks. Note the ads to the right of this search for Apple. Del.icio.us also rolled out a new home page that includes thumbnails and looks more like digg.
What's important to note here is that this is the first time there have been ads on del.icio.us since its inception. Also notable is that there are no contextual ads on del.icio.us tag pages yet. However, I am sure that Yahoo will soon move to monetize these pages since they are prime real estate on certain keywords.
Instituting ads on a service that is visited by hardcore techies can be dicey. So far, Yahoo seems to be wisely playing it conservatively to see how they fare. Digg has managed this transition nicely so there's no reason del.icio.us can't either. For more on my thoughts around tagvertising, see my post from last year.
