After seeing numerous MVNOs like Amp'd Mobile, ESPN Mobile, Disney Mobile and now Helio crash and burn, it would appear, from a US perspective anyway, that the virtual operator model is doomed to failure, with maybe the exception of new Helio parent Virgin Mobile USA.

Worldwide, however, MVNOs are expected to flourish. Well, survive, anyway. New figures from Informa forecast some 150 million MVNO subscribers by 2013, when they'll account for a whole 3% of the mobile market.

Informa even launched MVNODirectory.com, a Web site featuring all sorts of MVNO data. Apparently, back in November, there were some 255 active MVNOs around the world. The majority, 151 of them, were in Europe, 63 in North America and the rest spread out in other regions.

Based on those numbers, it's not hard to see why Informa expects 63 million of those 150 million subscribers in 2013 to be in Western Europe.

MediaPost has a detailed analysis of Virgin Mobile's bargain-priced, $39 million acquisition of the troubled Helio mobile virtual network operator (MVNO).

"By shutting down Helio's swanky retail outlets and kiosks among other cost-cutting moves, Virgin expects to reduce overhead by 70% by year's end," the report said. "The company plans to phase out the Helio brand except in Korean-American markets, where it remains popular."

By buying Helio and absorbing its devices and customer base, Virgin Mobile gets to offer its first 3G device, along with a subscription-based service that can hold on to more customers. Virgin said in the report that about 20% of their customers leave Virgin Mobile for a traditional post-paid contract as the major U.S. carriers offer.

This also leaves Virgin Mobile as the only MVNO standing in the U.S. As "virtual" operators, Virgin and Helio also both rely on the Sprint network for service, the report said—and both also focus on the youth market, which prefers high-end mobile media features such as what Helio was offering.

Well, it looks like there might actually be an explanation for all those mysterious Helio store closings. Fierce Mobile Content is reporting that Virgin Mobile USA and Helio parents SK Telecom and EarthLink have finally come to an agreement for Virgin to buy the rival MVNO.

The deal is reportedly valued at some $39 million and is expected to close in Q3.

It's getting more real by the day: FierceWireless reports that a Helio store in the pricey Cherry Creek shopping district of Denver, CO has a closed sign up today. That gives further credence to rumors that the company is closing down much of its operations.

As proof, the site took a picture of a rather ungrammatical, hastily tacked up sign on the front door that reads "The Helio Store is Closed. Contact their [sic] customer support." Maybe we're reading too much into this, but that use of the possessive pronoun "their" means that whoever wrote the sign either doesn't work for Helio, or is in the process of mentally distancing himself or herself from the company.

"The MVNO space continues to be plagued by problems," the article continued. "Gizmodo reported that embattled MVNO Helio is on life support after merger negotiations between parent firm SK Telecom and Virgin Mobile USA stalled. According to reports, Virgin's interest hinges on either a bankruptcy declaration or massive liquidation. In the meantime, Helio is planning to begin closing its retail locations and kiosks. Even if an official merger fails, reports suggest that remaining Helio subscribers will be migrated to the Virgin Mobile network."

Blyk is bringing its ad-funded mobile phone service to Germany, Belgium and Spain to, as the Register so quaintly puts it, expand "the concept of mobile-phone operator for freeloaders right across Europe." The company already announced its plans to offer the service in the Netherlands.

The service, which launched in the UK after a shaky start, offers subscribers a set number of free talk minutes and text messages each month in exchange for receiving targeted ads. If they go over the allotted freebies, they have to shell out a little cash.

European freeloaders outside the UK will still have to wait to get their free mobile service, though. Blyk won't be available in the Netherlands until later this year; folks in Germany, Belgium and Spain will have to let the anticipation build until early 2009.

And speaking of Virgin Mobile, the only MVNO left standing is now joining the major wireless carriers in offering a flat-rate plan, according to MediaPost: "Starting July 1, it will offer an unlimited calling plan for $80 a month with no annual contract. Unlimited text and messaging is thrown in for another $10 a month."

Astute observers will note that Virgin's plan costs $20 per month less than the four major carriers (Verizon, Sprint, T-Mobile, and AT&T) are charging for similar services. There's one major difference here, though: Virgin Mobile is also a pre-paid service, while the other ones all require a two-year contract.

It looks like that whole MVNO thing really is falling apart. After Amp'd Mobile, Mobile ESPN, and Disney Mobile all failed, the only two major ones left standing were Helio (which had its own troubles) and Virgin Mobile.

Now, right on cue, it looks like Helio is beginning to crumble—a fate that wasn't entirely unexpected. Engadget reports that Helio store managers received notification this week that the axe is finally falling, and that some stores will be shuttered in the wake of Virgin's takeover.

Virgin Mobile has launched a new series of promotions to market to kids on summer break. According to MediaPost, Virgin Mobile is leveraging Gadget Grrl's "Dads 'n' Grads" satellite media television tour, which begins Thursday and runs through June 6. "During the tour, Dana Forbes, a Los Angeles-based media personality known as Gadget Grrl who reviews and recommends devices, will visit 19 TV studios throughout the country."

The tour will highlight both the Samsung Slash and the LG Flare, according to the report. Later, Corinne Nosal, a Virgin Mobile spokeswoman, said that the company "will launch an online marketing promotion called 'Slide Into Summer' centered on the Slash." Virgin Mobile is a popular pre-paid option for cell phones; customers can buy the phones and then buy minutes a la carte, rather than having to sign up for restrictive two-year agreements with monthly fees.

Virgin Mobile USA has come up with an innovative way for customers who signed up for its Sugar Mama ad program to earn free voice minutes on its network. Since launching in 2006, Sugar Mama has been providing free voice minutes to users who watch online commercials and answer a short survey, MocoNews reports.

Now, the folks wanting free minutes have a new alternative, a Virgin Mobile "Fund My Phone" Facebook application. Users who post the Fund My Phone app on their Facebook profiles can earn free minutes when their friends click on the app and watch and rate the streaming content. The more friends that view the content, the more free minutes the user earns, up to 75 per month.

After days of downplaying speculation about a merger of sorts, Virgin Mobile USA has put out a statement saying that it is having preliminary talks with SK Telecom about "strategic opportunities" concerning Helio, the MVNO SK Telecom owns in partnership with EarthLink.

Reuters reports that SKT, the leading Korean mobile operator, isn't saying whether it's considering buying Virgin Mobile USA's business or attempting to sell Helio.

Here's the full text of Virgin's statement, issued this morning:

Virgin Mobile USA, Inc. confirmed today that the Company is in preliminary discussions with SK Telecom to explore possible strategic opportunities. Virgin Mobile USA said these discussions are in early stages, and there are no assurances that any transaction will result. Virgin Mobile USA will have no further comment unless a definitive agreement is reached.