Yep, I wrote about the role of luck in things as far back as 2009. Times were a lot thinner thin, and I happened to get lucky and was right at the start of the fat times. Ever since, I've been waiting for the bubble to burst. That said, as an established indie, that's why I focus in certain directions: diversification, serving niches that can't easily be fulfilled by others, not spending 18 months on one project, etc.