I think that the likes of bees4u should go and advertise their wares in the chat room at designated times only. Abut 01:00h on a Sunday morning for half an hour would fit nicely. See how many join in for the friendly advertising session.
This (the beefarming advert) is blatant advertising by a commercial enterprise, repeated verbatim elsewhere, no doubt. Those courses adverts should, at best be deleted or, at worst, allowed in a read only section, should be dealt with on a harsh basis if brought to the discussion forum, other than perhaps a 'PM me' reply, on occasions.
While I voted to retain user names, I do I think when it is seen to be connected to an outside website or similar, that name should be withdrawn. Difficult, yes (Mr Th*rne, purely as a well known example, might be a way for some to circumvent it, for instance).
Notice that the username will be terminated if not changed could be given (just like 'peak' was blanked out might suffice). It may concentrate minds if it is seen to be applied a couple of times (as appropriate, of course).
A resounding majority would vote for no advertising, I am sure. This type of posting is undermining that principle. If the username had any scruples in this context, they would already have asked the post to be withdrawn. I take it they have not.
RAB