A really smart MBA with a spreadsheet and proper motivation can make just about any idea look good and we have all seen campaigns, ideas, and even entire companies get funded in this way.
One of the things that often impresses me about the people I meet at Microsoft is their ability to be self critical. Some would argue that at times it goes too far. I think it is a characteristic other companies should try to emulate.
Last year at the Monaco Media Forum, Darren Huston, Microsoft's VP in charge of Consumer and Online, gave a great presentation and one of the things he said was: "average creative gets way over measured to try to prove it was great creative. Great creative -- we don't spend weeks measuring." The "we" at the end gives away that in addition to making this great observation, he was showing how Microsoft can be its own greatest critic. I believe this one corporate personality trait is Microsoft's biggest asset.
Whether or not the criticism is self directed, he was making a very good point, and we see it played out often in the technology marketing industry. Marketers get so attached to their ideas that they lose the ability to call a pig a pig.
This disability is self inflicted. By recognizing in advance that many ideas will not produce the desired results. And that no matter how experienced your team is, marketing is dominated by experimentation. You can in effect leave the door open to honest self criticism and ensure that there is a safe way to kill ideas that fail.