There's such a stigma around selling that it's really my least favorite part of my job, but sometimes you have to rally the troops to create change. There are people who just complain and don't do anything about the problem, and then there are the people who are willing to do what it takes to make things better -- even if it means writing a little promotional copy. If it failed to sell, that would mean that it didn't inspire people to learn, but it sold very well. My tweet announcing the article is my most retweeted, most favorited tweet of all time, and I've been on Twitter since 2008 and tweeted about 14,000 times. Obviously, the JS community is thirsty for better educational materials. I'm glad I can be part of the effort to make them available.