There's a new way of doing it now, which I just saw on this board. Seems stupid, but they are making what looks like a normal post, almost relevant to topic, then below that they have what looks like blank space but is actually a bunch of links to their spam sites that are text colored the same as the forum background.
These are a quotes of the ones I just reported:
[quote="rose2009"]Hi, your idea is very interesting , I really like it. Thanks a lot
[quote="jennyfifi"]Thanks for your sharing. Thanks for sharing this useful information. It's great.
(Mods feel free to delete the quoted text after you see it, if you need to)