LibraryThing's success—we recently hit three-hundred thousand members and twenty million books—has spawned competitors, more than forty at last count. We respect them. Some of the best include BookJetty (gorgeous), Anobii (simple and big in China), Socialogue (does CDs) and GoodReads (friendly and not small; they just hit 5 million books). We think we do it better—for example taking from more than 75 soures other than Amazon--but we also know we aren't perfect. To stay on top we have to work hard, and to be true to ourselves—loving books and being more open and collaborative than anyone else.
We respect our competitors with one exception: the site "Shelfari.com." We have always spoken our mind, so here's a piece of it: Shelfari has gained traction by engaging in unethical practices, including astroturfing (posting on blogs pretending to be users, not employees*) and putting out press releases about how they invented the idea. But the worst has been their spamming campaign.