I read this very nice year in review on the Ribbit blog. It highlights all kinds of things, but after a year of being part of BT one thing we have yet to hear about is revenue and customers.
In the space Ribbit competes in companies like Voxeo, ifByPhone (a client) and Twilio are all providing services to customers who are actually paying for them. They're not simply releasing apps, running trials in beta using an API from someone or announcing partnerships.
Don't get me wrong, I love what Ribbit is doing, but being inside BT means years of efforts before the old liners there embrace what Ribbit can do.