I own a forum called Promotion Era, which is about promoting anything (for now only websites), but it is still not very active and 95% of the community are webmasters. However, you are allowed to promote YouTube channels (no official section yet, post it in Website Promotion) and buy things such as links of your videos/channels and display it on the header of the forum, but I can't guarantee you success. Promoting on small communities won't hurt you, but at least it improves your channel a littl…