Why not direct? WOT Ebooks From Tor

The covers are incredible

Notable news
Tor.com have announced the launch of the ebook of the second book of the epic (though perhaps a new word should be created to describe the scale) series, Robert Jordan’s, Wheel of Time, The Great Hunt:

We’re happy to announce that The Great Hunt, volume two in Robert Jordan’s The Wheel of Time, is now available as an eBook from the Sony eBook Store and other online retailers. This edition sports a new cover and has been re-typeset especially for ebook production.

But riddle me this?
Why do they not just sell it direct? The multi-publisher bookstore provides just the platform, they have created an incredible audience and the property is a very, very good one. I cannot understand this decision. Sure the rest of Macmillan also avoids ebook sales listing instead other sellers on their site bit surely teh selling of a digital download is not THAT difficult? Is it?

PS: The covers are quite frankly fantastic for the ebook series, savvy to redesign them!