Not to get obsessive about tech IPOs again . . . but one deal now in registration, that of Internet-advertising company ReachLocal Inc., could be a predictor of whether the lackluster market for new tech deals will perk up soon.

Seven-year old ReachLocal, backed by outfits including VantagePoint Venture Partners and Rho Capital Partners, racked up $203 million in revenue last year. The Woodland Hills, Calif. company helps small- and medium-sized businesses get more out of their online-advertising buys, using a direct sales force to drum up most of its business.

The company also posted a $10 million profit last year, compared with losses in each of the previous four years—making it look, at first glance, like a pretty robust tech-IPO candidate in these tough times.

But there’s a catch: ReachLocal would have been unprofitable in 2009, it seems, if not for a one-time, non-cash $16.2 million gain from a recent acquisition. In fact, the company says in its latest S-1, filed with the SEC this week, that “we expect to incur net operating losses for the forseeable future.” (A company spokesman declined to comment, citing the regulatory quiet period surrounding the deal.)

Then there’s the broader, pesky issue of how ongoing economic turmoil will affect customers’ willingness to spend money on online marketing. ReachLocal says in its filing the recession hurt its business in 2009. Indeed, annual revenue growth has slowed recently, to 38% percent last year; revenue more than doubled in 2008. In early 2009, the company stopped hiring salespeople, it told the SEC, though it resumed hiring three months later. But it was at “more modest level” than in 2008.

Oh, and the company also disclosed that as of Dec. 31, it had “significant deficiencies” in its internal controls, according to its accounting firm. Apparently the problem has to do with how ReachLocal capitalizes costs for internally developed software..

So why does all this matter? Because it makes ReachLocal a bit of a reach (sorry) to actually stage a successful deal. At least one prominent Silicon Valley banker tells me he views the company as a “canary in the coal mine” for future tech IPOs. If ReachLocal, an essentially unprofitable Internet outfit, can actually get out, the offering could open the floodgates for other tech deals. There is certainly a backlog of tech companies in registration that are anxious to go public. But if the deal stalls, other startups will have to hang back.

The market’s recent dive certainly isn’t helping matters. For years now, though, only the highest-quality Internet companies have been able to stage successful IPOs—something ReachLocal should keep in mind.

One postscript: My previous missive on the lack of high-profile tech IPOs, posted Dec. 18, seemed to strike a chord with BusinessWeek. Peter Burrows followed my story with a similar one in the magazine on Feb. 4. He cited Yelp as another company opting to raise money privately, for now, and even quoted my friend Lise Buyer.