Are you using the "right" SVD?

Recommendation engines are all the rage. From Netflix to Amazon, all the big guys have been pushing the envelope with research initiatives focused on making better recommendations for users. For years, most research appeared through academic papers or books that neatly organized these papers into their respective techniques (e.g. collaborative filtering, content filtering, etc.) to make them easier to digest. There have actually been very few pure text books on the subject given it is a fairly new research area.