SMS cost
I was under the impression that as SMSs are transferred using a control channel that's always open when phones connect to a network, the real cost of sending a text is genuinely zero to the operators - the fact that a phone is connected to a network means its capable of sending and receiving texts for no additional cost above what has already been invested in making the network capable of sending and receiving calls. Sadly I don't see a situation by which operators will ever choose to start charging the marginal cost for an SMS.