I was asked recently in a Goodreads forum why I primarily published my novel as an eBook. I responded saying it was for time-to-market reasons. Getting a quality paper copy ready has taken over a month because I have to wait for Lulu to ship me proof copies.
But there was another reason I released an eBook first. I expected mistakes creating the various electronic formats and I assumed fixing those errors would be easier than getting a paper copy ready. Turns out I was right about that.
Now I find out that despite my testing of the Kindle version, the book has odd indents on a real Kindle viewer. When I heard this, I decided to re-release the Kindle version. My thinking is that the eBook is like software and this error is a bug. So I am obligated to fix it.
I also found out that I need to make some other adjustments. Suddenly I'm my own technical support department. I don't mind that roll, it just took me by surprise.
But in retrospect I will not be releasing any more books exclusive in one format or another because so many people still want paper copies. In fact one of the reasons I'm having a hard time getting reviews is because many places that review books want a paper copy. They even say they don't review ebooks and that's all I have at the moment.
So if you plan to self-publish plan accordingly.