There's a post referenced in tomorrow morning's link post that touches on interactive fiction. That piece claims IF is a new idea that is changing the market. The former claim isn't true, obviously, but the latter claim got me wondering about the size of the interactive fiction market.
While the money may have gone away, the format did not. IF migrated online back when that meant dialing into someone's computer, and the games followed the transition to the web. I myself played IF games on BBSes in 1996, and around 2000 I found new iterations of titles like Zork on the web.
And then, with the rise of mobile gaming, IF came into a second Renaissance.
Not only are there more options for writing your own IF (there's even a publisher focused on voice-activated stories for Alexa), people are buying IF like never before. We don't have complete revenue data, but some of the IF apps even reached top twenty or even top ten rank for highest-grossing apps in iTunes App Store.
At this point the IF market is worth, conservatively, anywhere from $100 million to $150 million. While that is relatively small potatoes compared to the fiction ebook market, the ranking data suggests that some developers are making millions of dollars from their app.
I don't think you can say that it is changing the market significantly, there is money there.