Steve -
What sorts of promotion did you do? I'm sure I'm insulting you by even saying this, but it's for the benefit of those reading too, so here goes...
It's not enough to just publish your books and get them listed on Amazon. You need to do everything in your power to promote them. Luckily, it doesn't have to cost a fortune, nor even necessarily take huge quantities of time.
There's an extensive chaper on Promotion in my book, The IndieAuthor Guide, and I'm giving away free electronic copies till the end of December via this Wall Street Journal/Marketwatch article (see the link in the 'Books and guides' section):
http://www.marketwatch.com/News/Stor...rkm7RO8k4sUMiw
Get the book and take a look at that chapter, as well as the one on Creating Your Brand. I'm having a great deal of success in indie authorship, and I hope others can do likewise with their books. That's why I wrote The IndieAuthor Guide! I hope you will reconsider indie authorship...it's been very fulfilling for me. Good luck, and happy holidays!