Though link farms do nothing for your page rank and directories frequently fall under the same category, e-book directories are a great way to ensure that your e-book receives attention.
We've included lots of links to get you started.
http://www.ebook2u.com/ - Ebook2U is a free e-book only directory – which means you can target those affiliates and people looking for highly targeted niche content. You can promote well in this directory.
http://www.mindlikewater.com/ - This huge directory accepts free and paid listings. With a vast array of categories and areas, you can list your e-book within many different areas to maximize your niche exposure.
http://www.wisdomebooks.com/ - Wisdom e-books is another site that allows you to list your e-books – its business category contains a lot of free and purchasable e-books, but doesn't really have much niche targeting capability.
http://www.jogena.com/ebookdir/ebookdata.htm – Mainly focused on marketing and business categories, you can sometimes list your e-book out with these categories.
http://www.ebookpalace.com/ - E-book palace is one of the few places that allow you to list your mini e-book for review – its highly focused categories give you a range of options to place your e-books in front of people that are interested in your niche.
http://www.ebookmall.com/ - Boasting 150,000 books or so – some converted hardbacks to e-books, this is a great, huge directory. This lists every kind of book – from marketing to fiction titles, that have been converted to to e-books and offered for sale.
If this wasn't enough, there is another, larger list of e-book directories that are considered less popular, but may also be worth researching other directories to list in.
http://www.marketingforrealpeople.com/ebook-directory-list.htm.
By simply submitting your e-book to a collection of directories, you'll find your exposure explodes, and you get more highly responsive traffic to your site, or downloading your e-book.