Yelp’s IPO filing: no tricks, but big questions linger

Yelp’s S-1 for its upcoming IPO is a breath of fresh air. After five months of studying the S-1 of daily deals site Groupon, I’m glad to see local-business-reviews site Yelp come out with a reasonably clean document.Groupon tortured many accounting rules and made up some of its own (forcing it to amend its S-1 repeatedly and delaying its IPO), but Yelp seems to be playing by the books.