Pactas, recurring billing solution provider, offers the Pactas API that allows developers to include Pactas functionality within third party apps and websites. Any need for recurring billing (e.g. carsharing, music flatrates, cloud services, etc.) can be simplified and streamlined with the Pactas solution. Pactas enables users to manage subscriptions, track payments, and map pricing. Access to the platform can customize to each users' situation depending on need, resources, and integration opportunities.
Email, which is one of the oldest services available on the internet, is a key mechanism via which you can reach out to your users. Over the last year, the number of services providing this infrastructure as a service has grown to include 6 email sending APIs. The newest, Amazon Simple Email Service, validates the market.