We have recently been getting quite a few spam posts - not much can be done about these as they are not bots but real users paid to spam links on forums to improve Google pagerank, etc.
Please don't reply to these post as it's just playing into their hands. Don't even reply "spam" or link a picture of a tin of spam.
All you need to do is ignore them and report them to the moderation team using the "report to moderator" link that appears at the bottom of every post.
Once we get them the posts will be deleted and the user banned/deleted.