why tag your runs?

I don't tag my runs very often.  Tagging is a function on the Nike+ system that lets you record information about the run - weather, location, how you felt. 
After our race last month, I decided I need to run more hills - they really got me on the race route.  So I am trying to run a hillier route at least once a week and I want to keep track of my progress.  So, at least for the hill run days, I am going to try and take that extra time and tag my runs.