Some interesting articles about the rise of adult coloring books:

CNN
Once obscure, adult coloring books have reached new levels of popularity. But do you know exactly why a page and some pencils can do your mind some good?

 

CNN
Many new coloring book titles are being marketed to stressed-out, work-addled adults, who benefit from the quiet zen that a coloring session can bring.
The Big Story
NEW YORK (AP) — Adult coloring books are giving Harper Lee a run for the money on best-seller lists this summer. Dover Publications has sold more than 3 million adult coloring books with titles like “Flower Fashion Fantasies.”…
My gut feeling is that with a bad economy and other stressful events in our world, more and more people are looking for stress relief, and coloring books do the trick.  In addition, our book focuses on faith promoting principles and not just whimsical.