American Express Co. (NYSE: AXP) agreed to acquire Tock for $400 million from Squarespace Inc. (NYSE: SQSP), adding a service that helps customers book dining and other hard-to-get reservations at exclusive venues.

Tock, which provides reservations, table management and event ticketing to around 7,000 restaurants and other entertainment outlets, complements Amex’s Resy business, a 2019 acquisition. Restaurants are a major spending category for Amex customers, exceeding $100 billion in volume last year, Howard Grosfield, president of U.S. consumer services, said according to Bloomberg News.