I don't use the Strava app to record my rides. I use a Garmin watch that I also use for running. I upload to the Garmin Connect site and then import that data into Strava.
I started importing more regularly once I saw some friends on there and when the Bike Forums group got setup. I also import into Endomondo which in turns gets imported into the National Bike Challenge site.
I'm just trying to make sure the world knows how many miles I ride. Hmm, maybe I should auto-post to Facebook too. Or tweet it?