I find the architecture to be really interesting and useful to learn from. However, they are way too expensive. 1000 tweets is not very much data. I'm building a realtime app now and easily am processing tens of thousands of relevant tweets a day. While a service like Datasift could alleviate a lot of heavy lifting on my part, the cost just doesn't make up for it. It feels like their business model is currently focused on use-cases requiring highly specific targeting, but not intended for use where services need high volumes of certain types of data. Shame, that.