I'm guessing people here are familiar with the idea of 80% of the results coming from 20% of the effort. Although the numbers don't hold in every situation, the basic idea works for most. I'm guessing people are also familiar with the Lean Startup, which emphasises quick 'n' dirty versions to enable rapid testing. People might not be familiar with Boyd's OODA loop (observe, orient, decide, act) -- but the idea is you want to move through the loop as fast as possible, and gain a strategic edge on the opposition.
I'm guessing people are also familiar with Apple, which follows a different philosophy -- aim for 100% every time, even if it means your products cost twice as much as the competition.
These philosophies aren't really opposed. Sebastian had a good post about this (which I can't find right now). You want to aim for 80/20 crappiness, or 100/100 awesomeness. You don't want to get stuck at the sucky zone in the middle.
However, how can you decide which things to 80/20, and which things to 100/100?