First of all, this is NOT a book.
I wouldn't even give it the honor of being called a short story. A short story presents protagonist(s), antagonist(s), plot, and resolution. You have a protagonist, I'll allow the presence of zombies to be the antagonist, but you do not present a plot (unless I am being VERY generous, and saying it was the attempted survival of the protags), and there is no resolution to the non-existent plot. This was about 17 pages and it was a serial. Even THAT is being generous, because while I am not a fan of serials, I have come across a few great ones, and to paraphrase (and date myself), Lloyd Bentsen, your serial is no serial.
Advertise your product correctly and while I will most likely avoid it until it comes out in an omnibus edition, I might take you seriously as an author. Not, however, when you issue seven 'books' that have (being generous here) on average, a length of 18 pages and want to call each one a 'book' and charge me .99 a pop.
I will even avoid your omnibus edition, because for about 130 pages, with your dishonest advertising, I will not pay $3.
In conclusion, your writing isn't that great anyway. For shits and giggles, I grabbed the sample of Argosy, your '#1 best-seller'. I've read better stories from junior high level English students.