I'm Stuart, co-founder of chatterbox.co. We've been using Mashape from the early days when they were back in beta, distributing our Sentiment Analysis API (http://www.mashape.com/chatterbox-co/sentiment-analysis-free). For a startup, getting to market as quickly as possible is great.. what you don't want though is a half baked product. Mashape allowed us to focus on building awesome sentiment analysis, so that we didn't have to bother about billing, rate limiting, etc and all the DB infrastructure that runs behind it. Certainly worth checking out, especially if all your stuff uses JSON anyway (which it should!).