What are some alternatives?
When comparing I Download Free and Ebook3000, you can also consider the following products
FreeBookSpot - Attention! Now all new books are free during first 5 days only. Sad but true.
Ebookee - EBOOKEE is a free ebooks search engine, the best free ebooks download library.
Tavaz - Tavaz - in Universalglot means «Search»
Z-Lib - ZLibrary Part of Z-Library project. The world's largest ebook library.
8FreeBooks.net - ebooks site that helps to give many pdfs
AVXHM - Free E-Books collection