I didn't look to far into this, but I believe he was referring to applications that do mostly reads benefiting from vertical storage.
My guess is that maintaining that data (update/delete/insert) would not be as good. But I really don't know much about the issue.
Also, someone noted that he now works for a company that deals with what he is discussing. I don't believe his is lying or anything.. but he is discussing/pushing information on what his current job is.. this is normal
beware the shouting of newpapers/magazines/etc... they are trying very hard to sell advertising
