Here is some interesting research on mobile advertising. According to a recent survey, a staggering 82% (!) of 11-20 year-olds would be happy to receive advertising in exchange for top-up credit (76% for discounts/special offers). There was more to report on the survey of course, which you can read e.g. here.
The most interesting conclusion is that the kids apparently fully understand the mechanics of advertising: advertising business is paying for eyeballs. If you want my eyeballs, you have to pay me.
They do not really seem to give a hoot WHAT ads they actually receive (although at least 71% would not mind to receive ads on things of interest to them) but more what they get in return for allowing it. This would appear to create a small dilemma because it is somewhat difficult to communicate to the advertiser that one wants it to subsidise the youngsters’ top-up credits (“so who was that ad from?” “Can’t remember but was worth 2 quid”). At the very least, advertisers would have to take a different approach to the messages (as in brand message, not as in SMS) and the type of campaigns they create in order to take this into account.