Yelp (YELP) wants to take on OpenTable (OPEN): the local reviews leader is spending $12.7M (mostly in stock) to acquire SeatMe, owner of a Web/iPad reservation platform for restaurants and nightlife venues. Yelp notes it has ~1M U.S. business listings in the restaurant and nightlife categories, giving it plenty of reach to leverage SeatMe's platform. The announcement comes a week after Yelp launched a platform for taking orders and processing transactions, and two weeks after Groupon launched a high-end restaurant reservation service. OPEN -5.5% AH. YELP +1.4%.