0-100 subscribers.
Now this is truthfully one of the hardest barriers to pass as a Youtuber, don't be fooled. My first 100 subscribers took more time than the next 1000. It's very hard to generate traffic to your channel. At this stage you can't even use Reddit to promote your videos, Reddit folk generally tend to upvote less when they see it's a video with no likes/comments/views. Also it's nice to have subscribers upvoting for you, regardless of how big the subreddit is.
) then it can be really worthwhile. If you do YouTube videos focusing on DIY and post it in the /r/diy sub then you've a better chance of people being interested and checking it out. I advertised my channel on the /r/dnd, /r/dungeonsanddragons and /r/rpg forums and within the space of a single evening had picked up my first 35 subs (after a few days I'm at 47 and seem to pick someone up every few days). Now I think my videos and editing are pretty good, so that's not to say to say just posting in niche subs will make you an instant hit, but it's given me a jump start at least.