They couldn't buy the last mile, but they could have gone for an infrastructure play. You buy your broadband from the local phone or cable company, and they give you an AOL email account, the default portal is aol.com, they nudge you towards the all-in-one AOL client, etc. The local cable companies don't have to figure out anything but being a dumb pipe, and they can get a revenue stream less coupled to selling overpriced dialup. (They did have a "bring your own connection" plan at some point, but it was probably an easier sell to include it as part of a $75/month DSL/cable subscription rather than as an independent line item.

Maybe use their temporary dial-up riches to line up long-term rights to premium content. I suspect before YouTube took off, nobody knew the potential for online video, and they could have probably locked in contracts at very low prices.