Part of the fun is seeing how the author is going to manage a New and Different story while sticking to the basics of the formula. Of course, much depends on how tight the formula is. . . .
Got a short story crying out for a sequel -- several -- because while the heroine is settled at the end, other questions are open. The sequels would all revolve about a room filled with costumes and masks for amateur theatricals. Put on one and play act a bit, and it becomes a -- more significant choice than you were planning on.
Attempting to brainstorm characters to go and have stories, in which the backstory of How It All Happened can be revealed.
In the course of which I found that the formula appeared to be -- one nice character to have the story, and several nasties to cause conflict. Not a bad formula per se, with good conflict inherent, but -- I need to stretch the brainstorm to go farther afield.