[Will Write for Gruel]

I think Guido makes a lot of sense. The counter argument might be that there are people who shop exclusively at one online store, and if your book isn't there, you lose them as a potential customer.

Also, if someone never looks at Diesel, your book being at Diesel is irrelevant to that reader. It only becomes relevant for those shoppers who shop at a variety of online stores. If I shop at Amazon, B&N, Kobo, and Apple, your book could be on Diesel, Sony, and Smashwords and your sales wouldn't be diluted anyway -- I never shop at those places.

I think what Guido is getting at is when your marketing efforts end up directing a reader to your work. If that is how a reader finds you, it makes sense if you can concentrate the results. If your marketing results in an extra 50 sales a month, if you can push those sales to Amazon it will make a dramatic impact on your sales ranking if you're not already in the top 5000.

In terms of readers randomly finding your books for sale, I don't think we can focus those results into a few places. The reader with a Sony e-reader may only shop at Sony. If our books aren't there, he may never see them anywhere else.