I check " Show unread posts since last visit." and 80% there is advertising some gambling or bets services , does it so popular here ?
Most of the signature campaigns here are from online casinos. They are hosting their campaigns here because it is profitable for them. Any service or company cannot keep advertising on a platform if it is making loss for them overall.
There's actually an option in the profile settings to hide signatures if a user doesn’t want them showing up while browsing the forum. Just a quick bit of exploring, and you can get it done in seconds. It’s true that gambling signatures are everywhere since most active posters are in signature campaigns right now, so if it bothers you, hiding them might be the best option.