Deciding on equity % for non-founders

I'm curious - why is a pre-launch startup hiring a COO to begin with? Don't you have to launch in order to have something to operate?

(I'm of the opinion that founders should avoid hiring anyone for as long as possible, instead bootstrapping off their own abilities until they gain some traction in the marketplace. In addition to saving money, this also gives you a better idea of precisely what you *need* so you don't hire for the wrong qualities. It'd suck to hire a COO with experience scaling Java enterprise apps to 99.9999% uptime, only to find that your actual business model demands a Python consumer webapp with few uptime requirements but massive social scaling challenges.)

For an example of offering too little equity, see the Equity section at http://blogs.xobni.com/asmith/archives/5