When I was in the corporate world, I took part in many meetings that were both "creative" and technical. One learns very quickly that superior ideas and concepts rarely are judged on their merits, but are often hostage to the local politics, ambition, power struggles, and personal rivalries that happen in any organization. It takes a skilled and insightful manager to separate the truly good ideas from the chaff that gets kicked up as part of the process of making decisions. The usual result is that the person or group who are best at marketing themselves (and that includes cutting down and "eliminating" the competition) and know who to influence, are the one(s) who prevail.
In this battle for mind-space, it really pays to know who's really going to be making the decision(s), who are the key influencers, what are the deals that are being made that may or may have nothing to do with the issue at hand, and what kind of criteria are being used to decide among alternatives. As Christina says in her post, "selling" the design is a whole process in itself. It's also worth noting that often the meeting or decision-making process is just window-dressing to give the appearance that the due process has been followed, whereas the true decisions have been taken, and the deals have been struck earlier.
In any "sales" effort, you need to know who the "opposition" is, what their likely tactics will be, what is their strategic advantage, and where are their weaknesses. Then, you need to determine the ground on which the battle will be fought - and the ground chosen should take away the strategic advantage of your opponents, while allowing your forces their maximum effectiveness. And know how solid your support is and who your allies are - people being people, you'd be surprised how often the support is much softer than you would think, and the allies can melt away or even change sides. Of course, that is also true of the opposition.