A few times per year, I look over my bookcase and if there are titles I am interested in replacing with eBooks, I start poking around Amazon (I have a Kindle.)
Sometimes, I am reminded of books I am searching for, or authors I want more of - and if they have out-of-print titles, I'll take a stab.
I've posted before about my tardy discovery and enjoyment of Fred Saberhagen's work.  Over the past few years I have been collecting his 
Berserker tales, 
Empire of the East, 
The First Swords trilogy and The 
Lost Swords series.  I have two books in the 
Lost Swords series to find.  Sometime during the year (summer, maybe) I happened upon Kindle editions of the first four.  As luck and timing would have it, the 
Swords books have been (re-)released in eFormat over the course of this year.  The covers are primitive, even for eBooks, so I was mildly suspicious.  But, they have all been released now (except, I believe, 
An Armory of Swords, which was an anthology.)  The eBooks are being created and published by Saberhagen's literary estate, 
JSS Literary Productions (which, I think is essentially his wife.)
Too bad there is a disconnect as JSS L. P. also run the Berserker website - the official Saberhagen site, and I see no news announcements about the eBooks.  So, I'm spreading the word for the curious, or fans, or fans who have lost their original print Saberhagen books.
I will still find hard copies of my missing two novels, but it's nice to know I can at least fall back to the eBooks if I really am desperate.