When is it time to call it a new edition?

[pmmg]

At what point do you feel you've made enough changes to a story, after its been published, that you ought to uptick the edition number? What is your threshold?

 

[ThinkerX]

The first time around, the edits were so severe - several per page, plus plot fixes - that I deleted the old books and released new ones. (Twice.)

This last time around, as it was mostly trivial grammar bugs (1-2 per 8-10 pages), I just updated the interior. (No new edition.)