Today M:Metrics debuts a new service tracks ad display on mobile sites, or on the devices themselves.

M:AdTracker will be deployed on 120 mobile portals and websites, including those from ESPN and other high-level publishers, as well as a few lower-tier ones.

The software measures ad display four times daily and returns raw numbers to M:Metrics, where data is analyzed and scrubbed by a team before conversion into client-ready reports.

Ads must link back to a webpage to be counted by the software.

Early reports show a number of Fortune 100 companies advertising on mobile platforms, breaking conventional wisdom that mobile advertising tends to be primarily for mobile products.