I should probably make a point of coming back to the book promotion topic at least once a week since it's the main job of self publishers. I discovered how to sell books through my website years ago, and it's remained my primary marketing method. As much as I like preaching about online marketing, the last thing I want is for self publishers to declare me a guru and work on their websites to the exclusion of every other marketing approach.
Everybody over the age of 5 knows that there's no "one right way" to do anything, yet self publishers often read a couple popular marketing books, jot down some of the most obvious suggestions, than focus all of their efforts on a pursuit of questionable value. Book reviews are a good example of that. I only went through the review process (pre-press copies, query letters, etc) with one book, and I got some reviews in really top publications. From a book marketing standpoint, it was a complete washout, for the simplest of all reasons. The title wasn't commercially viable, I had done no market research and the book had no audience.
Since then, I've made money on every title I've published, without ever sending a book out for formal review. What's more, I've seen the review process fail to produce sales over and over with self publisher friends, and not for lack of positive reviews. It's not that surprising when you think about it. I've never purchased a book based on a published review. It seems to me that the main marketing value of book reviews is to inform people that Title X has been released. If the reader doesn't already know the author of Title X, or hasn't been waiting on tender hooks for another book on the Title X subject, why would the review lead to a sale? The exception to this rule would be if you can get a review in a publication like the Library Journal, which basically exists as a catalog for librarians to order new titles from.
In the end, the way to be successful marketing your titles is to do the promotional activities that YOU are good at. The only thing I can really tell you about how to sell books with 100% certainty is that it takes persistence. I can't tell you how many self publishers I've heard from who flee at the first sign of battle, normally some bratty kid at a chain store saying, "We don't stock self published books." If you went into self publishing because you couldn't handle rejection (in the form of postcards from trade publishers), you went into it for the wrong reason.