If you weren't around then this may be hard to believe but I cannot overstate how ubiquitous was the distribution of AOL CD-ROMs. They were everywhere. It felt like you couldn't open a magazine without one falling out. You'd stumble upon them on the sidewalk. AOL must have stamped a billion of the damn things. (Edit: I was afraid I might be exaggerating but apparently it really may have been a billion. https://www.vox.com/2015/5/12/8594049/aol-free-trial-cds)
About 5 years ago I was pacing the Knoxville marathon and toward the end it was just me and a college student, maybe she was twenty, and somehow I brought up AOL. She'd never heard of it. She'd never heard of CD-ROMs. I was like, so there was this movie called You've Got Mail[1]. She hadn't heard of that either. I felt really old.
1. 1998 movie where AOL is a plot element. If you're up for a romcom that's a nice time capsule of the late 90s, you could do worse. Also has PowerBook G3s and the sound of modems.