Jeremy Stoppelman and Russel Simmons conceived Yelp after Stoppelman caught the flu in 2004 and struggled to find a trusted local doctor recommendation online. Incubated inside Max Levchin's MRL Ventures, Yelp popularized crowdsourced local business recommendations.
Yelp makes money primarily from Advertising (selling cost-per-click performance ads to local business owners who want top placement in local search results and category directories, with Services accounting for over 60% of ad revenue), supplemented by Transactions (Request-a-Quote project leads and consumer deals) and Other Services (Yelp Reservations and Waitlist subscriptions for restaurants).