Virgin Mobile, in a joint venture with Sprint Nextel, will give subscribers the opportunity to earn free minutes by agreeing to view and interact with ads, either via text messaging on their phones or on their computers, MediaPost writes (via MediaBuyerPlanner). Subscribers can earn up to 75 free minutes per month via the initiative, dubbed SugarMama.

One minute is earned for every 30-second commercial viewed, according to the New York Times. Viewers must then answer questions to prove they were paying attention. Pepsi, Xbox, and youth antismoking campaign Truth are the first advertisers.

Industry analysts, including Roger Entner of Ovum Research, aren't sure the initiative will take off. The consumers willing to swap their time for phone time may not be big spenders. "If you're too cheap to buy a minute of air time, how are you going to afford an Xbox?" Entner is quoted as saying.

The program, which is the first ad-supported cell phone service, will begin June 14.