Nielsen and comScore Duel Over Mobile Ad-Tracking

Marketers have been pouring money into mobile, but they’re still hungry for better tools to track the reach of their ads. Now there are signs of progress at the big measurement firms.

Nielsen will announce it is partnering with BrightRoll and TubeMogul -- two digital ad-sales firms -- for a technical trial before the expanding its ad-tracking system, known as Online Campaign Ratings, to mobile this summer.

ComScore, a Nielsen rival, announced the expansion of its measurement product, Validated Campaign Essentials, to track ads appearing on smartphones and tablets.

The two initiatives are evidence of how important tracking consumer activity on mobile devices is becoming to advertisers -- and how measurement companies are scrambling to provide more of that information.