- MailChimp API: Last month we covered 16 email APIs and here's another for that list: the email marketing service MailChimp. As they describe "Sync campaign stats and subscriber information between MailChimp and your database. This helps you download a list of unsubscribes to clean your inhouse lists, build client portals and pull campaign stats from MailChimp if you send emails on behalf of clients, aggregate and compile campaign stats, send 'we also recommend this...' campaigns, and pass account status data to MailChimp so that only active members get your emails."
- AgentFactor Travel API: A travel booking engine with wholesale fares and routes whose affiliate service for partners includes an API. Note that they provide API documentation only to registered affiliates.
- QuarkRank API: A recommendations aggregation service with API and widget access to their "intelligent engine which crawls the web for opinions on various products/services and automatically summarize them feature-by-feature using its proprietary natural language processing technique."