Are we solving the same problem?
This is the biggest disconnect I know of.
It happens all the time in B2B sales, in service marketing, in getting along with your boss and even in hiring someone.
One side thinks they have figured out a solution. They spend a long time talking about the solution, architecting it, refining it, pricing it, pitching it, delivering it. The other side ends up not liking what they get. The disconnect: the first side says, "this solution is exactly as we described it!" the other side says, "it doesn't work right."
The disconnect is caused because people focus on the solution instead of the problem you were given to solve. It's a lot easier to talk about features and hours spent and someone's resume and a lot more difficult to dig into the problem itself.
This is where the obligating question becomes so critical. "If we can deliver a dam that stops the water flow, will you be delighted?" "If I can hire someone who can answer ten calls an hour and keep customers coming back, will that work?" "If this book cover receives an award for best design, will that be a win?"
The difficult conversation about the problem is far more useful than the endless effort on solutions. The reason is that people don't tell themselves (or you) about the problem they're actually solving. Sure, they'd like an employee that does x, y or z, but you know what, they'd also like that person to be really good looking and willing to do our bidding, waiting on us hand and foot. Sure, we'd like a personal computer with a lot of computing power, but we'd also like it to be light and sexy and covetable...
The more clarity you can get about what a successful solution looks like, the more likely you will be to have a delighted customer when you're done.