Hi, it is natural that if you manage Forum, there are always registering people whose primary aim is to advertise at the forum. Someone do it politelly, someone bulk spam forum and do it offtopic - this is ofcourse bad for the forum visitors and it decrease forum quality. The duty of admin or moderator is to discover these people who harm the forum.

In my case, when i find some advertising post which is offtopic, i look at the nick name and click it. Then i click View recent users posts. And whn i see they are pure advertisement and duplicate or offtopic. I go delete this member including all his posts. When i see he is trying to make also usefull and ontopic posts. I delete only spam posts and leave him alone. Another alternative if he bulk spammed and some of his posts are usefull, i delete his spam and BAN him.

What are your ways of dealing with spammers and offtopic advertisers? Or do you have any note to my way of dealing with spammers?

I recommend installing Forum module that is using stopforumspam.com database and also creating custom antispam question on registration.