Re: rim jumps increase vertical?
There's a ton of exercises that can improve your vertical, one of them being rim jumps. The thing is, that if you have never done any specific training you're likely to improve your vertical by just working out no matter what exercises you do . As soon as you have worked out before and improved it's getting more difficult to improve and you need to pick your exercises more carefully. that's most likely also the reason why jump soles work for some and don't really work for others.
If you really want to improve your vertical by more than just 1-2 inches, then you should study some literature (e.g. vertical jump bible) and follow a training program. The key is to work on different parts of jumping (e.g. explosivness, strength, speed, etc.) only if you can combine these elements you'll become a great jumper. But it also should be mentioned that a big part of it is genetics. that's the reason why some guys jump out of the gym without any training at all.