"and said "if you pay £5 a year, you get access to all these sites..." and it included a bunch of things that I could see myself using... then it's possible I'd do it."
In the old days newsgroups - rather than web pages - were a major source of everything. It soon became obvious that only a few big players had the resources to catch all the postings in all the possible groups. That was worth a subscription to give access to as many groups as you could afford the time (and ISP dial-up charges) to follow.
The only advertising was from spammers who gradually flooded the unmoderated popular groups. Some of them were reputable companies who had outsourced control of their internet advertising to less than scrupulous outlets. The damage to their brand names was probably considerable.