If Mark read the book and recommended it on his own because he liked it, I'd take that more seriously than I would a blurb from people who may have been asked to provide one. As for this business about "an unedited online venue," who cares? Is it really being suggested that the same words, the same recommendation, would carry greater weight if they had appeared in a review in a newspaper or magazine? Actually, the reason one would have confidence in what Mark says on his blog is precisely the same reason one would have confidence in what he would say in a review. Which, of course, is why I invited Mark to review for me when I was The Inquirer's book editor.