OpenTable Reaches 15 Million Restaurant Reviews

In 2008 OpenTable launched it's review program - this week they have reached a massive 15 million restaurant, cafe and pub reviews. The difference between OpenTable reviews and other reviews from say Zagat is that OT reviews can only be given by customers of a restaurant where they have taken up their booking reservation made via OpenTable. This means that not just "anyone" can review and that customers really must have eaten there, aka "verified diners".

OpenTable is a leading provider of free, real-time online restaurant reservations for diners and reservation and guest management solutions for restaurants... OpenTable has more than 25,000 restaurant customers, and, since its inception in 1998, has seated more than 350 million diners around the world.   - OpenTable

What do you think? Are reviews worth the effort?