If you do a search for "Cookery Book" in the Amazon.co.uk Kindle store there are 724 matches. If you do the same search in all departments there are over 90,000 matches. I suspect a gap in the market, but I also suspect that the public may need the advantages of a cookery book on Kindle explaining to them. Here are my top 3, I would be interested to hear yours.
1. Ready made shopping list for your ingredients
2. All of your recipes in one place
3. No more pages splattered with ingredients!
Its not that people would be less messy using a Kindle, but they would probably take more care of it than newspaper cuttings, cookery books, magazine cards, etc.