Depending on who you ask, Clearwire's $600 million initial public offering earlier this month is either a ringing endorsement of WiMAX or another overblown service provider IPO, the likes of which we haven't seen since the height of irrational exuberance.

Launched in 2003 by cellular legend Craig McCaw, the company is betting big on WiMAX technology to deliver wireless Internet services in competition with DSL, cable and emerging cellular options.

The company spent $300 million to acquire the bulk of its 2.5GHz WiMAX radio frequency spectrum from AT&T, making it the second largest holder of that spectrum behind Sprint Nextel, which also has bold WiMAX plans.

That spectrum is enough to reach more than 200 million people, although the company has only built networks in 34 markets - primarily in California, Oregon, Washington, Texas and North Carolina. Late last year the company started offering service in Seattle, its first top-tier city.

But the question is, do the numbers add up?

Clearwire brought in $33 million in revenue in 2005 and tripled that to $100 million in 2006. But the company is burning through cash as it builds out, with total losses since launch of some $460 million, including a whopping $284 million loss last year. And it still only has 206,000 subscribers.

Even if Clearwire can triple revenue again this year, the IPO windfall won't last long: the company reportedly will need $800 million to cover 2007 debts and other expenses. And it likely will have to issue even more stock to keep its momentum.

These factors lead many observers to question the viability of the venture, with some comparing it on paper with the network IPOs at the beginning of the decade, many of which went belly up.

But Clearwire has an ace up its sleeve: Intel owns almost a third of the company which ensures client support will be built into devices and ultimately drive demand.

Other players in the WiMAX world see the healthy Clearwire IPO and Intel's backing as a sign that WiMAX will make it.

Jeff Thompson, CEO of Towerstream, says "the Clearwire IPO is good for the market, good for companies working with WiMAX." Towerstream uses wireless to deliver T-1 equivalents to businesses in New York; Boston; Providence, R.I.; Chicago; Los Angeles; San Francisco and Seattle.