How is cracking your joints unhealthy?

My joints have cracked for years. Usually feels good when I crack them. As I age, more joints are cracking. Its getting a bit ridiculous. So far on the web, consensus seems to be that without pain, there's no real problem; but don't crack your fingers constantly.
I find taking chondroitin glucosamine MSM helps me not constant crack my lower back, neck, and ankles that was starting to worry me. i'd like to figure out if its ok for long term use...