Niche media is any media product that you like and no one else does. 'No one' here refers to the people in your personal social circles - it's easy enough to find some fans of most anything online.

It may be disheartening after discovering an amazing thing to learn that your friends don't like thing or have no interest in checking out thing. Consider an alternate frame: thing is a gift made just for you. Just as you don't fret over sharing gifts that are given specifically to you, don't fret over proselytizing others to the glory that is thing.

Someone or someones took the time and effort to create this great thing and you get to experience it. That's a special sort of transaction similar to conversations with close friends or inside jokes with coworkers. Don't despair that others are missing out on thing, celebrate that you get to enjoy it.