A lot of people are on an in-between plan, having cancelled the dialup portion but kept the online service through a cheaper plan. AOL made that free in 2006, but only if you notice and change your billing.
My parents had AOL dialup in the '90s, and when they got cable broadband around 2001 or 2002, they switched to AOL's $10/mo bring-your-own-access version, because they wanted to keep their email addresses and some stuff they used in AOL's client at the time. AOL made that free in 2006, but didn't switch you automatically: you had to call up and ask to switch to the free plan, which had become identical to the pay plan except for the $10/mo fee. I'm sure many people are still paying that $10/mo, either because they don't know the free plan exists, or don't realize it's identical.
1. People are stupid.
2. There's a lot of the US, land-wise if not population, that still has no broadband alternatives. Dialup is all there is.
3. See #1. That bundled set of applications which sorts out the wild, scary Internets for you is comforting to some.
Only some crappy "security" software for broadband users (I wouldn't call their subscription model for broadband users scam buts it is a bit shady to take 12 bucks a month for some discount coupons and "$750 Extended Computer Protection").
