The underlying question of your comment is whether this is a stable business model. You already indicate that Twitter has the ability to disrupt/shutdown your service, which puts you in a difficult situation to build something of value. If you are ever wildly successful and dependent on one platform, then that platform will extract value from you or replace you. Consider this a rule, not a guideline, because it always makes business sense for the platform to do that. Recent examples include Zynga paying the Facebook "tax," Craigslist effectively shutting down PadMapper, and the slew of Twitter 3rd party apps that have been crippled by limited/revoked access.