Mercatus Technologies is a software development company that offers cross-channel marketing capabilities for retailers. The Mercatus Concierge for Mobile is a customizable mobile application service that features Near Field Communication (NFC) and Quick Response (QR) technologies. The Concierge API allows retailers to present a consistent face to customers, across all marketing channels. They can also get faster feedback about their customers' behavior. The API uses RESTful calls and responses are formatted in XML and JSON.