Constant Contact is a comprehensive email marketing platform designed to help businesses of all sizes to create, execute and optimize email campaigns. It offers a wide variety of features, including segmentation, automated campaigns, contact list management, and integration with social media. Moosend is also an email marketing platform, but it focuses on providing its users with powerful, easy-to-use tools. It offers a simple drag-and-drop interface, newsletter templates and list segmentation, as well as the ability to set up A/B tests and other features to help optimize email campaigns. Constant Contact is geared toward larger businesses, while Moosend offers more features designed specifically for small businesses.