I think when this was originally published in hardback as one volume, it was pretty expensive (about £50 - it seems too have come down to around £25 now). So splitting it into four Kindle volumes at £6.58 each probably sounds like a bargain. However, I felt pretty miffed when I discovered that the introduction by Scott Adams is exactly the same in both volumes of this I purchased for Kindle (Dilbert 2.0: The Dot-Com Bubble, 1998 to 2000
and Dilbert 2.0: The Modern Era, 2001 to 2008: 20 Years of Dilbert
). What's more, in the "Dot-Com" volume, it constitutes about a third of the actual volume; at least in the "Modern Era" there's a much larger cartoon:introduction ratio. Surely it wouldn't have been too much to ask of the publishers to ask for some volume-specific introduction, rather than just lazily cutting and pasting the same content into each volume?
e-publishing is all very well, but it seems that it's often an excuse for publishers to do as little as possible to try and wring a bit more profit out of something that they already have in their catalogue. More effort please.
By the way, do check that this can be delivered to your device - only Android,Kindle Fire and iPad. Not for standard Kindles or Kindle readers on PCs.