How do I decide what book will release next?

I’m seeing a surge in sales in a lot of older works that I believe is attributed to the giant boost and success I’ve had on Amazon and BN the last few months.
More readers have found older works which is GREAT.
My schedule for 2014 is jammed packed. 2015 is already half filled as well. Those who work with me behind the scenes to make my books publishable can tell you… I’m one busy gal. Note: I love being busy. My daily word count goal to stay on track with this schedule is over 5k a day. Other authors can tell you, this is a lot. With no weekends or sick days.
Q: How do I decide what book will release next?
A: There are a variable of factors.
Is this a book or a series that is getting nothing but hammered in reviews and is suffering low sales and / or high piracy? If so, it moves down the release date list.
Is this a book from a series that is rockin’ the reviews and sales charts? If so, it moves higher and higher on the list.
I think everyone can agree that makes sense.
Is the book contracted or does it have a special agreement with a third party for publishing? If so, then there is NO wiggle room for me on those books. They must come out when they are to come out no matter how much another title may be calling my name to work on it.
Thank you everyone for understanding and for being so supportive of what I do and how I do it. Please know that I am working very hard behind the scenes to bring you all the books you want.