Originally Posted by artifact
Things where I see color being useful for ebooks:
Cookbooks and other food porn
Crafts and Patterns (knitting, cross-stitch, woodworking?)
Home Repair and Decor
Game guides and manuals
Coffee table books
Work documents with color graphs, photos, etc
Manuals and instructions
I'd call that mass-production.
What proportion of those people currently buying Kindles would pay say twice as much to be able to read an improves version of the books listed above, but wouldn't rather just buy a tablet instead?
I'd guess maybe about 5%. That isn't a mass-market item. It could be a profitabe niche, but still a niche.
If these had came out at the same time as the original iPad, for a fraction of the cost, they would have had more appeal, but now they seem like a product in search of a market.
An eInk reader will provide better battery life, but with tablets offering 10+ hours, the number of people for whom that isn't good enough isn't huge.
Edit: There may be more interesting applications outside of book reading. A hiking GPS with a colour eInk screen would be a nice product.