Don't tell Strava this... but my thought for increasing the numbers of Premium subscribers would be that they'd only hold your data for... 2 years or so. So if you like looking back at 5 years of your favorite segments, you'd have to pay up. Strava could keep the data so you'd get it back if you let it expire and re-join.

I think most people buy Premium just to say thanks for a great app. Trophy cases and sorting segments by weight or age just doesn't seem to have much value.