title: Measuring time spent watching a video?
body: <p>I'm building my own Video sharing web site and I want to get for each video - estimated watch time.</p>
  
  <p>What is the best approach to get such measument as the user can just close your page any moment. </p>
  
  <p>Sending requests any 10 secounds of video playback, seems to me as really bad solution ?</p>
  
  <p>I couldn't find any html5 players offering such features.</p>
  
  <p>Any suggestions ? </p>