I guess the current preorder growth is on the lower side of the statistical average - probably soneone has a model for that. But just from a rough estimate of around 5000 Pandora Owners checking the site about once a week, and around 500 first-response Pyra adopters talking nonstop about it, reaching 3-5 people every day - that sounds about normal. Either by having old crowd members stumble over the news, spreading the word among friends and neighbors, or just plain luck - it's most probably in the 0,1%-0,01% rule of thumb margin. It would be an interesting excercise to hold that assumption against a site visitor counter...
But I digress - what I wanted to say was: There are only so many old crowd people and friends to talk to (I tried with 3 and didn't convince them yet)......