The utmost thing is the user experience, to have the most useful experience.
What you want, when you want it. As opposed to everything you could ever want, even when you don't.
I think Google should be like a Swiss Army knife: clean, simple, the tool you want to take everywhere.
Our theory is, if you need the user to tell you what you're selling, then you don't know what you're selling, and it's probably not going to be a good experience.