GNU lover ^^
I mean..
When Goin' on a channel (with the personal name of the owner) what do You expect to find?

i.e. You were watchin' a video Tutorial (that You loved) so You are goin' to that channel...

How do You react if You don't find other tutorials but all another kind of videos?

Do You sub on the hope to see more tutorials or do you just leave the page?

What is a channel for you?

PERSONALLY, I see a channel as TV radio station, so I should find a LOT of contents and not just a category =)
I guess I usually subscribe when I notice that the channel has consistent content. I don't mind a few different vids ever now and then. But if it's all over the board, I'm unlikely to sub unless I really like the person/people. And, for whatever reason, I usually don't subscribe to a channel until I've seen a bunch of heir videos. No idea why I do that haha. I think the only channel I ever subscribed to after seeing the first video was CinemaSins. I immediately knew I needed more of that in my life!
I'm really not a fan of inconsistency when it comes to channel content, unless I really like the person I'm subbing to. I don't mind a variety if I know that's how the channel is laid out - some people upload gaming videos on Thursdays and then comedy sketches on Saturdays. Stuff like that, I'm usually fine with.

I mean, I follow a bunch of different people. Gaming, education, beauty, vlogging - you name it.
But if I'm following someone for one topic, it's because I know they're good at it and are interesting in producing videos in that style. If they go a different route, there's no guarantee they'll be as skilled in that field, so it's a case of checking it out each time.
It's a great question because it's one that has plagued me with trepidation...

On one hand, I want to have an active channel - on the other hand, I want a channel that's consistent in what it offers. I think that's very important.

Meanwhile I have a series I'm working on, which is unlike my current content (a weekly vlog, and somewhat regular unboxings)... and I've questioned myself (and flip flopped a million times) on whether to put that content on my existing channel or start a new one for it. My fear has been that if I put it on my current channel, it may get a head start in terms of views and dominate the channels content BUT it may also turn off an audience if I have that and other stuff as well. It starts to get a bit muddy if the channel is a mishmash of content.

So if I put it on it's own channel, it may make it harder to get going because it's a brand new channel with no subscribers... but at least I can keep the content consistent.

Sorry for hijacking your thread with my own YouTube therapy session haha.
See I cover and do a lot of different stuff on my channel but its all in the category of vlogging so I'd either expect a channel to have a set routine of "Thursday - Vlog, Saturday - Gaming, Monday - Beauty" or generally sticking to their own stuff. Of course its fine to give things a try every now and then too :)
When I subscribe to a channel I think of it as subscribing to a personality if you get what I mean? Like I won't care what that person does in their videos as long as they're entertaining to me.
I see a channel like a business! How well do they present themselves? How high quality is the content? Does it speak to me or do they have another audience? All that factors to if I watch, and even more if I subscribe :)
I go to YouTube for many different things. If I'm just looking for instructions on how to do something, I probably won't subscribe to a channel, unless it's something like a cooking channel where there may be a bunch of different recipes. (I probably wouldn't subscribe to the channel that showed me how to fix my screen door, because that's not something I have to do all the time.)

For entertainment, I'm very personality-driven. I like people who do interesting things, and if they do a bunch of different things, that's okay. I can skip the videos that don't interest me, but keep up with the people when they're doing something I'm interested in.