The joint mobile venture between EarthLink and SK Telecom finished 2006 with 70,000 subscribers, and expects to hit the milestone in April. Additionally, it is making money at a rate that would allow it to surpass $100 million in revenue per year.

Helio's disclosure of its user base came as part of a larger announcement where it announced its own music store. The company also said it was encouraged by the rate of subscriber growth, which is increasing month after month.

Unlike its traditional counterparts, who only manage to generate about $50 of revenue per subscriber, Helio has managed to keep its average revenue per user at about $100 per month. This is helped along by its higher-priced calling plans.

Base calling plans start at $65 per month. From there, a multitude of services including MySpace Mobile, multimedia downloads, and gaming helps to push monthly bills to that $100 per month level.

While the numbers aren't overly impressive, it is in line with one of its chief competitors, Amp'd Mobile. That MVNO said at the end of 2006 that it had surpassed the 100,000-subscriber mark and had average revenue per user of "well over $100 per month."