I was lucky enough to attend a demonstration of some of Vignette's latest offerings, beyond their more well-known content management system, VCM. One of these is Vignette Recommendations.
Recommendations is best described as a behaviourist's wet-dream. It aims to anticipate the behaviour of a visitor to the site, and provide the content that the visitor will ultimately find most valuable. The thing is that this content may not actually have anything in common with what the visitor thought they were looking for - e.g. it may not share any keywords with the search that brought the visitor to that site.