Financial terms of the deal were not disclosed.

CardStar’s apps allow people to share coupons, while collecting information on their trends and behaviour on behalf of retailers.

The firm’s founders Andy Miller and Danny Espinoza, and the rest of the team, will become part of Constant Contact, with Miller serving as director of mobile products and Espinoza taking the role of SVP of strategy and corporate development.

Constant Contact CEO Gail Goodman said: “The CardStar loyalty platform takes advantage of the anytime, anywhere nature of mobile – making it an excellent complement to our growing suite of engagement marketing tools for small businesses. CardStar’s unique mobile application is a natural extension of our brand, bringing consumers and merchants together before, during, and after the sale to help drive repeat business.”