... or (shudder) even AOL?
You've got me there. I honestly have no idea. Masochism, perhaps?
Cost, ease of installation and avialibilty. And AOL does provide a high degree of hand holding for those who want it.
It's no cheaper than other similar ISPs. There is nothing to install for internet access, it's all built into Windows (I don't believe AOL supports other OS's) - you just have to run the "internet connection wizard" - the CD's are purely to get the ISPs name in the title bar of internet explorer, they don't do anything else. And it's definately no more available than other ISPs - availability is dependant on your phone line, not your ISP. I can't judge for handholding, as I've never needed to phone an ISP for help, so it's possible you've got a point there.