I see very little spam here and I have been using the forum for about 2 years now. Whenever I do see it I hit the "Report to Moderator" button. They always seem appreciative. They take down the posts and even send me a thank you email. The last spam I saw was a week or so ago; somebody had posted the same thing in 11 different places, so in the comment on the report field I just wrote "all posts from this user are spam".
I encourage you all to do it when you see spam (or offensive posts, which I think have mostly been eliminated from here as well). It's kinda like picking up litter in your neighbourhood; though you're not responsible for the mess, helps keep the place tidy for everybody to enjoy.