The best way to grow any social media is to build value in your project.  You can get people to join your social media, but they won't stay around if there isn't any ongoing value that they receive.

I have built a YouTube channel to over 1k subscribers by myself without any promotions or marketing in a very niche market by being super honest, open and giving people value straight up.  I interact with and keeping giving value to those subscribers, and the channel keeps growing.

There are quick ways to buy a social media following, but they are empty - giving you almost no value back other than an appearance that you are something you are not.