This is by far the most prevalent paid online service. Most everyone on the Internet has tried it at one time or another. Some people swear by it. Personally, I think it is probably one of the best for anyone new to online services. Navigation is logical and relatively easy to follow.
Email is reliable and minor updates are automatic.
There was a time when it was almost impossible to get online without getting about 10 busy signals first. Not just for the novice either. If nothing else, check out their AIM 4.0 Instant Messenger program. Compuserve used to be strictly a business site. It is a good place to advertise and it has some excellent forums.