This is a polite request from your moderators that you please don't reply to or quote posts which are blatant spam.
Just flag spam and move on. In extreme cases, feel free to directly PM the moderators.
Look, I know spam posts can be pretty funny, just check out massively popular fake Twitter spammer Horse_ebooks if you need any evidence of that. However, by replying to these threads, you're just exposing more people to this garbage by keeping the threads at the top of the forums, and if you quote spam posts, then you're creating more work for the moderators because now we have to track down and delete two posts rather than just one. Replying to spam posts is almost as bad as actually posting spam.
So, long story short: