you do both. don't ever bet on a quick exit. if it happens, and you get an offer you can't refuse, great. but you have to have your own course of action: turn it into an iphone app, sell the data via an API for others to embed in their app, etc. the big companies will take notice.
every business looks like a feature in the first few months. MS-DOS probably looked like a feature of IBM PCs at the time. when a feature becomes really useful, it turns into a product. when a product becomes really useful, it turns into a business. when a business becomes successful, it creates an industry...