Thought On Spam

First for anyone who hates spam feel free to give us your comment. Last week we had people spamming on where to get Nike shoes for a discount.

Here is what I don't get about spammers. Why even try when you know Admin or a Moderator are going to delete the post and most likely ban you from the site. Also no one is going to fall into the scam they post. Let me get your opinion about spam and how your feel about it.  

I think they do it for link building (seo) on sites that don't use a no-follow. Thats the only reason I could think of.  

Maybe, but I think once we destroy the post it makes a 404 error for there link and that doesn't look good for them at all.