Well,
we have different kinds of spam, some of them are easy to fight, others don't.
Robots posting porns, forex related commercials and alike are easy to fight. However, you canīt avoid the post. So, if some robot post about a commercial site, this post will be public for some time between 1 minute to 30/45 minutes but most of the time it's moderated in the first 15 minutes.
The other kind of spam is where a person post a couple of post and then starts to spam. This is a bit difficult to detect than the other kind of spam because you have to check what is all about the post.
Newdigital will correct me if Iīm wrong but right now spam is 50/50 both classes.
Good news is spam are coming in waves. Some weeks we only have 2/3 spam posts, other 2/3 per day.
I believe the best tool users have is the report tool. Or write a PM to the moderators but to all because if you wrote only to one and heīs sleeping (everybody needs to sleep) he would see the pm several hours later.
I like to note I've finished to read spammers have defeated Google Gmail validation. Imagine if Google and his millions cant control who is signing into gmail to spam what we could do.
Theīre some ideas around but we can't discuss in public for obvious reasons.