Couple of ways for Yelp to become profitable:
1. Partner with businesses like GroupOn, LivingSocial etc – I was looking through the reviews at Yelp.com and found that a lot them stated that they visited the restaurant the first time only because they received a coupon offer from Groupon. Parterning with each other would be profitable for both of them by attracting more customers and providing more business.
2.Convert to a freemium model – offer summary review information for free and charge customers a small fee for detailed reviews. Since Yelp has already established itself as a review site with a considerable following, this model would work.
3. Yelp would also need to beef us its sales force to attract more reviewers, partner with local business etc.
Yelp already has an advantage over printed editions since they cannot offer dynamic content. Though Yahoo and Google are established brands, they are not as well known for reviews as for search engines and other services. Yelp should retain its focus on offering impartial reviews on local businesses. From talking to several friends who visit Yelp.com, the primary reason is that they find the reviews reliable.