Yelp’s IPO filing comes hot on the heels of successful IPOs and high valuations for Angie’s List and Groupon. Yelp’s timing reflects both a tech-friendly market and the company’s current position as the dominant consumer-review web site. Yelp has 22 million reviews, and the supposedly imminent onslaught of competing review sites has yet to materialize. But is Yelp really poised for long-run success? My research shows that there are points in its favor — but there are others that should raise investors’ concern.