Total Time Spent considers all the time we collectively spend online and is a function of the number of people who visit a site, how often these people visit a site, and how long they stay on a site.

Although unique visitors and page views are critical pieces of the puzzle - these metrics often fail to accurately measure engagement on sites using technologies such as AJAX and online video.

Recommendation: Total Time Spent can be used in conjunction with Other metrics (such as Unique Visitors or Visits) to calculate additional engagement metrics, such as Average Stay or average time spent on a site per visitor.