It's Not Working.

I would like to have your comments about my newest book , Paradise, book one of the Aftershock series. It was published in September of 2016. Since then I've received four reviews, all good.  And no, they weren't from family.
My problem is that I can't seem to get anyone to read this book. I don't have bad reviews, I essentially have no reviews. Is the problem the subject matter? Many others have been successful with dystopian/post-apocalyptic stories. Is it the cover? Does it lack something? Do I need a new cover? Does the blurb on Amazon need to be changed? Do I need to change my profile picture?
I market on twitter mostly. I try not to over tweet my book and I retweet others a lot. I do use Facebook too, but not very often. I've tried reducing the price and even had giveaways. I attend writers conferences and online webinars, but the advise is always the same, lots of info with no application. 
Even though this is the first in a series, and not selling, I intend to complete the series. I personally like the story and the characters. Book #2 will be coming out sometime this Summer or early Fall. Book #3 has been started. So, I hope I can get a handle on what to do and what not to do in the near future.
I know there are many others out there who are in the same situation. We put all our effort into writing what we believe is a great story, only to be disappointed, not by negative comments, but by avoidance.  
I would appreciate your help. Thanks. Mike.
The Amazon link is goo.gl/vsDbci if you're interested.