mikemearls33 points19 days ago
Customer feedback, combined with an analysis of sales over the years.
We found that people wanted to buy only a handful of books. Most wanted to buy less than one a year.
In looking at historical sales, we found very few books that sold at numbers to justify their release. Which was surprising only until we studied what people wanted the product line to look like. AMA: Mike Mearls, D&D Creative Director.