The dot-com bubble burst in the early 2000s, sending the economy into a recession. The housing bubble burst in the late 2000s, crippling the U.S. economy. Is self-publishing a bubble? Could it burst? And if so, what effect would it have on the publishing market? These are the questions that have been getting a lot of attention as self-publishing continues to expand in popularity, reaching all-time highs in both books being published and sold.