I never thought I'd say this, but Dockwa actually does a pretty good job at what they do. I'm still opposed to the whole concept of planning ahead of time where I'll be any given night, but if it's got to be done, Dockwa makes it as easy as possible.
I've seen the operation from both sides now, as my own home marina started using them and I was involved in the transition. Frankly it's set up pretty much exactly the way I would, if I were setting it up. I would like to see them go the way SnagASlip went, with private dock and mooring rentals, and listing non-participating marinas, maybe even anchorages. Yeah, those don't bring in much revenue, but providing the customer with one-stop shopping for voyage planning might actually bring in more business. Imagine what they could accomplish if they supported an ActiveCaptain-like experience, but with reservations thrown in.