I had a client of mine in UK who wanted to send out a crazy 100,000 SMS everyday for marketing to opt-in subscribers. Of course, due to low margins he could not

I had a client of mine in UK who wanted to send out a crazy 100,000 SMS everyday for marketing to opt-in subscribers. Of course, due to low margins he could not afford a web based SMS service. The successful solution I provided him was using Kannel to set up a SMS server which used to operate around 120 3G modems to send out those many messages in around an hour. Now of course, this method has flaws of its own in the sense that it requires your SMS server to be connected to the internet 24x7 something which can be hard but you could use some local datacenters to do that for you. In India, typically web based SMS services cost around 0.1 cent for a single message so most developers use that but if you are targeting a global audience then the choice can be really difficult. Anyways if you do need some consulting or development on SMS applications feel free to reach out to me on info [at] akshayagarwal [dot] in