I check " Show unread posts since last visit." and 80% there is advertising some gambling or bets services , does it so popular here ?
Bitcointalk forum contains varieties of sub boards which means each related topic for discussion is channeled at the section it belongs. So when you see a gambling topic being discussed here, not that it is a major fact of discussion on the forum here. It is you who probably visited the gambling section where is designed specifically for gambling discussions.
However, technology is going on advancement and Crypto casinos has also been one trends in the online gambling sites.
So they runs a marketing advertisement here in the forum since the forum is sponsored by bitcoin and other cryptocurrencies.
There are a lot of sub board in this forum which shows the typer of discussion to be held in each board.
The gambling board is very large here, and it is the most posted board in this forum because most of the signature campaigns in this forum are gambling related, which are mainly betting platforms and casinos; and they always require their participants to post at least ten post in the gambling board which simply means that most of their posts will in the gambling board, and that is the reason the board is always busy.
But other boards are also active with same users that post in the gambling sections.