Skip McGrath has been selling on Amazon for several years now (and eBay for at least 15 years).
(Throughout my eBay/Amazon selling career, I've followed his strategies and read just about every newsletter and several of his books)
I don't have any proof of Skip's Amazon sales, but I'm guessing he probably does at least 10x mine.
He just wrote a FREE and neat post 'Twenty Tips for Selling on Amazon". It's a quick read but I guarantee you'll learn something new (I did with his tips 16 and 20). I printed it out and I keep it on my desk.
(I make NO money from his Twenty Tips guide, it's 100% FREE for you - no opt-in required).