Yesterday’s WS Journal had a terrific article on software for web sites that use e-commerce. Personal Journal section, 7/31/07. I’d share the article but I only have a print subscription (wouldn’t you think you could get online search perks if you’re a print subscriber!).

If you want to know how sites come up with you may be interested in this
recommendations, this is a definite read.

ChoiceStream is the software featured (and the company who placed the story, I assume).