Mobile marketing is one of the most promising emerging platforms, with display ad spend on the channel expected to exceed $1.2 billion by 2015, according to ABI research. As businesses prepare to dole out larger shares of their budgets to this medium, they may be pleased to learn that Google recently unveiled some new features to its ValueTrack tool that will help marketers calculate mobile display ROIs.

The tool has traditionally allowed businesses to calculate the clicks they garner from search campaigns and those that come from campaigns on the ever-expanding Google Display Network. Now, the company has announced a Mobile ValueTrack that lets AdWords users see what share of clicks are coming from mobile ads.

Miles Johnson of the Inside AdWords crew explains that marketers simply have to add the Mobile ValueTrack parameter to their text ads in order to take advantage of the new feature.

Additionally, the tool can automatically redirect people who are traced as visiting sites via mobile devices to mobile-optimized versions of business websites. This may be particularly appealing to AdWords users as an eROI survey shows that nearly one-third (31.6 percent) of marketers believe mobile-optimized experiences are important to their audiences.