My earlier post on the LIRNEasia's study of telecoms use by the very poorest people in Pakistan, India, Sri Lanka, Philippines and Thailand, generated a few public comments and some direct emails. In addition, I've now read through the rest of the public material about this project. Several points emerge.
SMS usage is almost totally a function of the relative cost of a voice call as Dimuthu Ratnadiwakara from the LIRNEasia team comments here.
Access to telephony is better than I thought. I remember saying (back in 1999) that half the people in the world had never made a phone call. Eight years later and things are considerable better. First we are rapidly approaching the point where 50% of the people will own their own mobile phone (sometime in 2008), but more importantly, most people, even at the lowest income levels, already have access to a phone when they need one.
Keeping in touch with family and friends is the number one reason to use a phone, by a large margin! I thought business would be up there, but no, the number one universal human need is to keep in touch with family and friends and that need exceeds all others.