Technically speaking, you did advertise a website. However, this specific incident is such a trivial reason to get banned. If you were advertising something like another community with actual intent of advertising it and getting more visitors, then the ban would be justified. In this case, it's simply not. A sign/textscreen saying "pornhub" or "pornhub.com" should only we worthy of a verbal warn at most. It seems that you had no malicious intent and simply slipped up. I would hate to see someone not allowed to play at all for such a small and minute error, especially one that you showed much remorse for and understand how to avoid the same issue in the future. That being said, you have my +1.