We have been using sms billing on our most of sites for around 10 months now. When we first started we only took a few bucks a month, seen an increase though the past 3 months, and rake a few hundred bucks each month per site. Easy money.
Downside, it takes forever to get paid out,
Not much control over pricing,
We are limited to 3 messages an hour etc,
and the country list is small. My own view is this kind of billing is going to take of more and more, but its needs more features, more control and better price options, oh yeah and a bigger country list.
We also setting up a "sms a model" Page to see how that wil go.
Give it a year or two and SMS billing will be bigger n better.
