I was on a 4-way and 8-way competitive team and we had sponsorship for most of the time we were together. When your training jumps are free, you do a lot of them. All of my winter vacations for years was to Florida or Arizona to jump.
As to what made me stop, the team finally disintegrated due to personality differences. It was fairly acrimonious and people whom I had been jumping along side for years, turned out to not be friends at all. I stopped competing and did other things. Got my PRO license and jumped into a few stadiums, a NASCAR race once, and more than one air show. I stopped doing those types of jumps, when an idiot from the FAA tried to tell us that our final turn to land had to be over 1000ft, which is insane and not safe. This was at an airshow and we were landing in an airport. He wouldn't budge on it though, because he was just a god damn whuffo on a power trip. I made a normal turn to final, which was about 300 feet anyway. I decided that was the last time I was going to put my safety in the hands of someone that had no clue what they were talking about, even if I was making money at it.
Later at my home DZ, I landed after a pretty good fun jump and started gathering my main and just felt... Nothing. The jump went well, but it just didn't mean a whole lot to me. I was apathetic. Add to that, I was dating the future Mrs CanopyFlyer and while she supported my jumping, she is no jumper. She's never been on a plane smaller than a CRJ. Where I've jumped from Sport Planes, that are just one step up from an Ultralight. A lot of people have pointed to her as my reason for stopping, but really she is what kept me jumping that last year. It was just time to move on.
Would I jump again? I'm no longer capable of jumping as I injured my back two years ago. While I would not be paralyzed or anything like that, a hard opening would carry the risk of making the pain I deal with every day a whole lot worse. It's hell to get old.