Your own social media outlets would be a good starting place to place links. Utilize your already existing base of followers or supporters (Facebook, Twitter, Instagram, Etc.) Then from there, you may be able to post your videos (not in spam like fashion) but elsewhere in forums such as TubeBuddy, Reddit, Niche Forums dedicated to your content and channel, etc. Then from there, interact, grow and build a base of more supporters on each platform you can. Interact with other like-minded channel content creators on silimar places, like Facebook, Instagram or YouTube. Especially smaller accounts, show support and connect and in turn it could also impact and positively grow your channel or brand!
Firstly promote your channel on different social media platforms like Instagram and Facebook. Utilize your social presence on Facebook and Instagram if you have great audience. Post on your unique content on your social media platforms. Reach and engage your audience but if you don't have much audience. You can also buy likes and followers from smm panel deals for your social proof.
No social media platform, no amount of word-of-mouth, ads, sub4sub or other promotional options can hold a lit match to the people YouTube can put you in front of. Sure, posting your video on Reddit or Facebook can get a few extra views. But not one of these options offers the shear magnitude of captive viewers that Google and YouTube offer, nor do they offer viewers who are so expressly looking for exactly what your video is about when it is served to them.
My point being that this is the answer as to why TubeBuddy is valuable; cater your content to a specific audience, optimize it for YouTube's indexing/Search and Discovery and create content based on underserved and underrepresented or trending topics.