For four years we have offered the synchronization service for no charge, predicated on the hypothesis that a business model would emerge to support the free service. With that investment thesis thwarted, there is no way to pay expenses, primarily salary and hosting costs. Without the resources to keep the service going, we must shut it down. This is something of a shock; it has been legacy common sense in the "web 2.0" world that, if there is a need you can address competently, the business model will eventually become evident. In the case of Xmarks, one of my favorite services, it never did. It isn't too surprising that they couldn't convince a buyer to try and turn a profit on them, but I'm a little surprised that Yahoo, despite owning an somewhat abandoning del.icio.us, didn't bite on this simpler and more elegant implementation.