Right now, I have first chapter excerpts posted on my official website with a linkout to the book's product page on Amazon where readers can use the search inside feature. The advantage of Bookbuzzr, of course, is that potential readers don't have to link out to an e-commerce site to read your sample. This offers lots of versatility, and that is always a good thing. My only concern, and this is probably a bit of author paranoia, is that I get a bit itchy at the thought of my work digitized that widely on the web. Maybe it's because I grew up in the dark ages, before the web, before personal computers -- you know, back in the days of the typewriter -- so, I have some control issues. Piracy or Paranoia, either way, both are very real. Maybe I should get back on my meds?
In any event, check out their FAQ pages. As a reader, I always flip through a book before I buy it, and so preview pages equal flipping in the e-commerce arena.