I recently bought it from Webscriptions, but I haven't read it yet. Unfortunately for me, you can currently get it for free:
To get the free book, send an email to
io9GodsWarGiveAway@nightshadebooks.com. You will get a DRM-free EPUB back in your email (usually in one or two days; they are processing requests manually).
Another recent Nightshade book can also be had for free:
Nightshade Books is celebrating St. Patrick's Day by giving everyone a free copy of Of Blood and Honey ($7.99 Kindle), by Stina Leicht (they couldn't figure out how to send us all a pint via email). To get the free book, send an email to
BloodAndHoneyGiveAway@nightshadebooks.com. You will get a DRM-free EPUB back in your email.