I've participated in a number of product reviews and book reviews . . . but none of them (besides Mary's tour) actually requested that I suggest the readers buy the product. They are meant more to produce a sort of buzz and product recognition, I suppose. Since big companies do this (think: General Mills, Nicholas Sparks' new book), I have to think it makes sense from a marketing standpoint. But what do I know? I'm just in it for the free stuff. ;)