I just updated ye olde Released Book page and the astute among you may notice that there are no more included links to purchase any of the Push Chronicle books. Now, before you panic, let me assure you that while you cannot currently purchase them, there’s a really, awfully good reason why not.
Unfortunately, I am not at liberty to say why that is or when that will change. All I can assure you is that it’s actually a really good thing and that they will be available again sometime Soon (TM).
Uhm, that’s all I can say about that. For now. Again, Soon (TM). Until then, good reading, good writing, and good luck!
J. B. Garner - Musings of a Starving Author 
I can probably guess why with some accuracy (since it is something I’ve toyed with the idea of a few times in the past). I will, however, respectfully refrain from stating my theory in open forum. It is your news to share (or not) as you see fit.