Name that company

I trace my roots back to San Francisco in 2004, when two former Paypal employees raised $1 million to start a service where friends could exchange reviews of businesses. Restaurants are my biggest category, but “home and local services” and shopping are each nearly as big. Today, with a market value recently topping $2 billion, I sport more than 200 million reviews and have partnered with Grubhub to deliver food to customers. My shares soared 64 percent on the day I went public in 2012, but then they fell back to Earth. They were recently up about 40 percent since their debut. Who am I?

Last week’s trivia answer: American Express