There is no simple, one size fits all answer to that question.
This online article, though, provides an excellent explanation of the mix of revenue sources and possible revenue. If interested in the pay out schemes, check out that link.
Last night I watched a video that was basically “What ever happened to these sailing channels?”, referring to the large number of (mostly) attractive young people who think they can sail around the world and pay for it by posting videos of their travels on Youtube.
Only a few of these channels achieve success and many eventually disappear for reasons ranging from insufficient income, partners splitting up, some getting married and settling down on land, thinking about families, and coming to grips with reality of – at some point- needing to save real money for the future and not just beg for donations on Youtube. Plus some have decided they would rather return to a private life.