My comment is awaiting approval at your site but I'll summarize by saying that "focusing your distribution" seems to be ignoring/discarding the wishes of readers who like shopping at sites like Diesel. They have a neat rewards program and if I wanted to buy your book there I can't? Sorry, but as a reader, and potential fan of your work, that wouldn't sit well with me.Guido Henkel said:Before trying to have your book listed all over the place, you might want to take a look at a recent blog post of mine about "focusing your distribution." You might find some interest thoughts in there.
Look at history in other areas. This has parallels to DRM. People got very angry at the Eagles and other bands for making their CDs only available at Wal-mart. It's one thing to make exclusive/special/bonus versions for certain stores but to only sell your books at certain stores? Recipe for reader backlash.
Readers don't backlash? Look what they are doing to authors with high priced ebooks.
Respectfully, best of luck if it works for you, Guido, but I doubt that's very good for readers if authors en masse start doing this. What happens if one of your big three turns on you? You stop selling there? Haven't you limited all your marketing eggs in three baskets?