I'm quite fond of the idea of Guerilla advertising a clan.
And the cola idea is an interesting way to go around it.
Hosts can feel free to remove them.
But for someone to advertise their clan, it's not a bad idea, so long as it's not done spammily.
As in, you create a macro, join a server, load the macro, then bugger off.
Best to spend some time on the server while you're there.