I have a feature on Vimeo on Demand. I have not done very well with it as most of my audience has purchased from VHX.com, since there are more features and extras on VHX. (and because we haven't quite been successful in building an audience...yet!)
BUT I believe you can only upload longer, larger movies with a pro account on Vimeo...so for me it's worth it because our latest feature is on Vimeo as a private link for film festival submissions, which I absolutely love. I HATED making several DVD copies and mailing them out for submissions.
It's easy; they're payout is convenient; I say any and all ways you can get your movie out there is worth it.