I have to agree with this. The customer/buyer is going to be looking at it from the perspective of their own users experience and will be mostly interested in how it will enhance their workflow. I'm in a similar position. I want some early feedback but don't have the whole backend settled yet. So I'm just going to dummy up some backend data and processes and present them onscreen to get the concept across. Once they've got the concept, they can be instrumental in designing what the processes and presentation will actually be. I mean hell, if I can't even explain/sell the concept, I've got the wrong idea or the wrong audience. Invaluable knowledge at this stage.
Ad blind. Totally. I'm almost always on a page for a reason and just want to get what I came for and then be gone; either back or digging for more substance. I suppose my mind is registering something of them but I don't seem to be conscious of this.