I would like to measure how much time a user spends on my website. It's needed for a community site where you can say: "User X has been spending 1397 minutes here."
After reading some documents about this, I know that there is no perfect way to achieve this. You can't measure the exact time. But I'm looking for an approach which gives a good approximation.
How could you do this? My ideas: 1) Adding 30 seconds to the online time counter on every page view. 2) On every page view, save the current timestamp. On the next view, add the difference between the saved timestamp and the current timestamp to the online time counter.
I use PHP and MySQL if this does matter.
I hope you can help me. Thanks in advance!
Two factors are working against you -
You can only collect point-in-time statistics (page views), and there's no reasonable way to detect what happened between those points;
Even then, you'd be counting browser window time, not user time; users can easily have multiple tabs open on multiple browser instances simultaneously.
I suspect your best approximation is attributing some average amount of attention time per click and then multiplying. But then you might just as well measure clicks.