Web measurement firm comScore is going mobile. The company is buying M:Metrics for $44.3 million plus 50,000 options of comScore stock. M:Metrics measures mobile Web usage, and will give comScore the ability to track mobile visitors, pageviews, and ads clicked. Its three major products are (from the press release):

MobiLensTM, a syndicated monthly online survey that captures overall mobile phone usage, including device information, data usage, media consumption and demographic characteristics of a representative sample of more than 40,000 mobile device users. MobiLens is available in the U.S., U.K., Germany, France, Spain, and Italy.

MeterDirectTM, the industry’s first on-device meter that passively measures the mobile Internet behavior and media consumption of more than 4,000 existing Smartphone panelists. The M:Metrics metering technology is compatible with more than 280 device models. MeterDirect is currently available in the U.S. and U.K.

M:AdTM, the first competitive tracking service for mobile advertising that continuously monitors clickable display advertising from a broad representative set of mobile Web destinations to reveal leading advertisers across a variety of market segments. M:Ad is currently available in the U.S. and U.K.

ComScore is a publicly traded company with $87 million in revenues last year. It expects the M:Metrics business to be profitable by the end of 2008 on an EBITDA basis. M:Metrics reveneus are forecasted to reach $11 to $12 million this year, and are expected to contribute $6.5 million to $7 million towards comScore’s revenues for the full year. Founders Will Hodgman and Seamus McAtee will join comScore.

M:Metrics, which is based in Seattle, was founded in 2004. It has raised $18 million from Prism Venture Partners, i-Hatch Ventures, and WPP.