Maybe you shouldn't ask
Fast Company has a terrific cover piece this month about Jeff Bezos. My favorite part is when he talks about asking other people (experts, even) for their opinion about new projects.
Inevitably, people say no. Don't do it. I don't like it. It'll fail. Don't bother.
When I think about every successful project (whether it's a book or a business or a website) the people I trust have always given me exceedingly bad advice. And more often than not, that advice is about being conservative. Or it involves focusing on things that will require a lot of work, rather than things that will make it remarkable.
The incentive plan here is pretty clear. If someone dissuades you from trying, you can hardly blame them for the failure that doesn't happen, right? If, on the other hand, they egg you on and you crash, that really puts a crimp in the relationship...
I think the problem lies in the question. Instead of saying, "what do you think?" as in, "what do you think about Amazon offering 1,000,000 different titles even though some of them are really hard for us to get..." the question ought to be, "how can I make this project even MORE remarkable?"