My kids are 11 and 13 now, and you might think after a few weeks they would be bored with it already. However, even though it has been amazingly hot outside, they have continued to jump on it! They are learning skills like front flips and my daughter is working on her cheerleading jumps. It's great exercise and they come inside all sweaty, even when they jump in the cooler temps. My son has had knee problems for the past couple of years, so I'm hoping that the jumping is improving his muscle tone and endurance without straining his knee. He seems to think it's working. His goal is to slam dunk in basketball eventually!
I do think there is something to be said for making children learn patience with things they want. Both of my kids are really busy, and you would think they wouldn't have time for jumping on a trampoline. But they make time for it because they really appreciate having a trampoline FINALLY.
I know a lot of people have gotten hurt on trampolines, but the net on this one is very safe. As you can see in the picture, the covered springs are on the outside of the net. Also, the net really does work as far as "catching" a jumper if he misjudges his landing. I believe it's caught both of my kids' faces so far LOL. We do have it staked down so it doesn't end up in the neighbor's yard. I've heard many horror stories about that as well. If you get a trampoline, please make sure to stake it down!