The Merchant Data team at Groupon uses MongoDB to create a comprehensive database of places and merchants, which has a direct impact on their business. This data is used for various products such as Salesforce CRM and public merchant pages, making it more efficient for salespeople to prioritize leads and create deal-structures. The use of MongoDB in this architecture has a significant revenue impact of millions of dollars. Groupon's reliance on place data is evident in its mission to build the most comprehensive database of places and merchants in the world. The team uses MongoDB at all levels of their data system architecture, from input processing and serving, which enables them to process large amounts of data efficiently.