Are you looking at this subject from a marketing or management of growth point of view? In other words are you asking how to grow or how to manage and track growth?
I like Ash Maurya paper on pricing. Here's a link to a nice article written by him: http://venturehacks.com/articles/pricing-experiments
Not sure if it fits your product or company, but I LOVE this book by Ben (on Clarity) & Alistair