Virgin Mobile USA has released some figures on how its Sugar Mama program is going in the year since it launched…the opt-in program offers customers free minutes in exchange for reading ads. An average of over 1,000 new customers has signed on to participate in Sugar Mama each day since its inception, earning over nine million minutes of free airtime. That’s about 25 minutes a customer. Virgin said the average click-through rate is 5.5 percent. This seems to support the idea of ad-supported mobile services, but 2-minutes of usage a month does not make a mobile service—the vast majority of Virgin’s business is from paid minutes. The ad revenue is a supplement—it’s still a while before a mobile service can survive purely on ad minutes. What ever happened to Xero anyway?