Single accounts per device id/email/etc. with a usage throttling on free accounts would greatly limit competitors from blasting your system with spam that you'

Single accounts per device id/email/etc. with a usage throttling on free accounts would greatly limit competitors from blasting your system with spam that you'd have to pay for. As far as not losing money in general, twillio is a great service but it's also one of the more expensive. There are competitors now so shop around a little bit. Overall though you'll most likely have to have a good advertisement system, some type of affiliate sales, or initial paid users to keep it running for awhile without investment backing.