What is engagement, and how can we measure it? To measure the proportion of impressions that consumers engaged with and for how long, we use a metric called "dwell." The metric measures the proportion of rich media impressions that were intentionally engaged by mouse-touch, interaction or click as well as the duration of the engagement. Unintentional dwell (lasting less than one second) is excluded.
This measure of engagement provides an estimate of the share of impressions that were, with high likelihood, seen by users, as a user's natural tendency is to follow the mouse cursor movement with their eyes. Dwell measures the proportion of impressions that had a meaningful mouse-touch, lasting more than one second. While there are undoubtedly users who see an ad without a mouse-touch, dwell allows us to gauge the number of users that are very likely to have seen the ad.
Dwell rate and duration
Research by MediaMind, Microsoft Advertising, and comScore shows that engagement does have an effect on brand metrics. Results of the joint study indicate that users who were exposed to campaigns with high dwell are three times more likely to search for brand-related keywords as users who were exposed to campaigns with low dwell. Moreover, campaigns with high engagement boosted advertisers' site traffic by 69 percent and improved brand engagement --increasing page views and time spent on the brand's site.