Different people would appreciate Proof of Brain for different reasons. If you're interacting with a specific group of people, use reasons they care about and leave the other reasons for other groups of people.
If in the course of commenting or replying to someone, you could make a casual reference to something you read or a discussion which took place at Proof of Brain. Either use []() or just drop the URL in your comment or reply. The more often you do this, the greater the chance that people will visit PoB and maybe become regular posting members.
Most of my posts are at LeoFinance, but periodically I refer to posts I made at Proof of Brain or to posts I read at Proof of Brain. I do the same here for LeoFinance content.
When you post, spend time making an attention-getting headline. If your headline is average or worse, no one will stop to click it to then read your post. If you want to promote Proof of Brain, a catchy headline is crucial. Don't make it click-bait, but make it catchy or intriguing.