Scribd simply does not have the content that is readily available on other web sites. It is a sort of last resort stop for most folks when it comes to ebooks. I would look around here for ideas about other places to sell your book.
I use a wide variety of sites for ebooks including: www.fictionwise.com
, and many others.
There are plenty of online self publishing sites as well and never underestimate the power of self promotion, start your own web site and host your book there.
Scribd is a good place to start, but it should not be your one and only place.