Same strategy as 'the site getting a mention' in a magazine really Paul.
It's free advertising for the T-Bar, yes. But it's also interesting for others to view these topics. Not everything has an agenda. In this case though, the agenda is activity. Do they need to be members? Some have joined, some have just looked and left. Many, many, many return as guests frequently.
You can't know that there's not someone out there who will make a positive contribution or become a member, perhaps even buy a car at some point. One long time lurker became a fully fledged member today and he brought a positive contribution with him too. It's in the lpg discussion thread. Different people have differing reasons of course. Who knows what will come of it all. Time will tell.
At any cost. Not sure what that means exactly but I would imagine it relates to site speed and bandwidth usage perhaps?
More activity, more bandwidth, more members, customers.. small fish, big pond or the alternative?
lol just as a point of interest an mx-5 forum member recommended our sponsor to his brother.