My guideline is whether I do a lot of whatever activity calls for a special shoe. For instance, for my new bike I will wear my plain ol' New Balance all-purpose athletic shoes. But if I start putting on piles of miles or start doing longer trips, it will make sense to buy bicycle shoes (which have cleats in them which lock onto the pedal for more efficient pedaling). They're barely usable elsewhere but they're the right tool for the job. I never used to discriminate among different types of athletic shoes, but when I wore through a pair of NB running shoes within a year or so, I was told that people go for running shoes partially for their construction and partially for their lightness. That lightness did not serve an overweight casual wearer (me). I know basketball players typically need a shoe which will support their ankles. That's another thing I don't need to go grocery shopping. But if I played basketball a lot, it would be worth getting shoes optimized for that activity.