Well, before targeted ads there were blogs and they were well read. Not so much anymore since Google decimated that channel.
Think "before blogs". Windows 3.1 rose to dominance when the Internet wasn't a factor for the vast majority of computer users (and even less for everybody else).
How could they possibly have acquired customers back then?!?
With money… lots and lots of it spent on brand level marketing in print media as well as with direct sales reps.