Mobile phone service carriers experimenting with serving up ads to their customers are trying a variety of models, still looking for the best fit for them and their users, reports The Seattle Times.
Carriers such as Virgin Mobile have found success in encouraging ad viewing on phones by offering customers free minutes in exchange for watching commercials. These are ads designated by the customer, who registers preferences online in addition to taking surveys. Such permission-based ad models are attractive to carriers, which are worried that customer displeasure could lead them to drop the company in favor of another cell provider.

That's just one model that's been adopted, though; others are opting for banner ads on mobile sites, sponsored mobile search results and more. Some view such targeted ads on mobile devices as extremely attractive, since their hyper-relevance would lead to significantly high click and conversion rates. Carriers cling to such local focus as an advantage over Google and Yahoo, which can't geotarget as specifically.

Privacy remains a concern, with carriers seeking to maximize the data they collect on user demographics and behaviors while not becoming intrusive.