The critical thing to get right when epublishing is the listing on the ebook online retailing sites - especially Amazon's kindle store.
Your book needs to be categorised, tagged, and described so that it can be picked up by search engines. Ebooks are digital products for a digital age.
If you have a well-written book aimed at a defined market segment, and provided the book is properly formatted, you should be getting off to a decent start.
The next job is to promote the listing just as you would for a printed version.
A final point: don't over-price your book. The big ebook sellers are sold at a low cost. And why not. Forget about what used to happen. Go for quantity sales every time. Then you have a chance of the thing getting taken up as the book gets widely read.