ROI on the Kobo doens't revolve around selling millions (certainly not at $100, which is where the price is heading); but rather as an additional 'hook' to the Kobo bookstore. The same goes for B&N's Nook and the B&N e-bookstore. The problem is that you aren't 'forced' to buy from Kobo or B&N, so Indigo and B&N can't capture their audience as well as Amazon can (and Apple - from an application point of view).
Losing $15M/quarter on $200M of gross is not sustainable, and I understand the short-term investment required, but ultimately, shareholders will want ROI and that can only happen if the Kobo e-bookstore is successful. How do retailers like Target compete against Wal-Mart? They don't directly - they go after a slightly different market. B&N and the Kobo e-bookstores have to offer something that Amazon's store doesn't have - does anyone know what that is?