I agree, it depends on what you want to do. Vimeo reaches a smaller audience, but those who go there are looking for full-length, more well-produced video content. If all you're trying to do is get eyeballs on videos, you may consider directly uploading some video content to Facebook, with a link to your YouTube channel for full versions of what you've uploaded, as a "teaser," of sorts. Facebook videos get more views (native Facebook videos, not embedded from YouTube) by multiple factors than YouTube videos do, so if you're not concerned with monetizing every view, that may be a good bet.