I think this is definately useful for businesses that need to use a service sporadically and have a "project based" model.

I might need a LOT of help for 3 months, then no help for 2 months and then again for another 3 months.

I had to cancel my LegalZoom account because I didn't need it for awhile, but then opted to not sign up again even when I did need it again a few months down the road.