They are mainly accounts run by
@Ric and the moderator teams, posting stuff in order to generate hits and responses. Similar to the Talksport business model. This then helps to pay for the servers and software and maintenance and support needed to keep this Forum operating.
If enough people subscribe then Subscribers may get a kind of personal moderator concierge service (Superbia option I think) to filter out some of the shite so that those kind of posts are far less annoying.
Only some of the above is true.