I thought people who still have AOL email addresses were out of touch until I traded correspondence recently with someone who still has a Prodigy e-address.
Considering the service was shut down a decade ago after being bought by AT&T (the Prodigy.net domain doesn't even exist any more), I asked him why he hadn't updated to a newer domain. He explained that he has over 4,000 contacts in his Prodigy address book and doesn't want to move them as long as it works.
I remember the pain of doing that when I abandoned my old Compuserve account, which I acquired in 1986, before you could choose your user name and instead were assigned a numeric address with a comma in the middle (I was 73030,email@example.com). After that, I had an AOL address for years before buying my own domain (HarrisOnline.com) and using it ever since.
Somewhere, there must be people using Earthlink, Delphi, and Genie -- via dialup.