comScore, a leading internet data analysis company, has announced the purchase of M:Metrics, a similar company focused on mobile internet traffic tracking, for $44.3 million plus stock options.

The deal will give comScore analysis results even more reliability, thanks to the fact that mobile internet usage is becoming more and more significant nowadays. The stock options refer to the fact that certain unvested option holders of M:Metrics will be able to buy comScore shares.

comScore expects that the deal will make the company the leader of the market of mobile internet traffic analysis. M:Metrics, whose clients amount to more than 180 companies, is formed of MobiLens, supervising cellular phone usage, M:Add, a statistic tabulator for mobile ads, and MeterDirect, which monitors web traffic of mobile devices.

M:Metrics’s income for 2008 is expected to be somewhere around $11 million, and its contribution to comScore’s earnings will be between $6 million to $7 million.

The two co-founders of M:Metrics, Will Hodgman and Seamus McAteer, will join comScore’s management staff. M:Metrics will keep most of its departments at their current location in Seatle.

The acquisition could shatter the doubts some people have regarding the precision of the internet usage metrics that all companies similar to comScore offer.

Last year, the Interactive Advertising Bureau wanted comScore and its rival, Nielsen, to have an audit regarding the ways the two companies obtain their data. M:Metrics’s acquisition will probably increase comScore’s results credibility, given the fact that the company can now survey internet traffic of almost any kind.