I read F & SF, most of which is written in series, or set within an internally consistent universe. I've been a regular library user all my life and got really fed up with not being to read a series in order "Oh yes, that's book 2, book 1 is in a library 20 miles away and book 3 is even further, would you like us to order them in for you at £1 each?".
With my Kindle, unless it's something I particularly want, I don't bother with it unless the series is complete. There are plenty of completed series out there to keep me busy for the rest of my life - and more being finished all the time.
I've already got more on there than I'll read in the next 2 years.