The official white house spokesperson said it was a secret message:

White House Press Secretary Sean Spicer stated, "I think the President and a small group of people know exactly what he meant."[4]

Because admitting to a typo in an unfinished, now deleted tweet was apparently impossible for the man in charge of nuclear weapons. That's worth a bit of coverage.

High interest in that topic and therefore more ad impressions.

(Assuming you're right that there was non-stop coverage, I don't know.)

There wasn't non-stop coverage: a couple of stories when it came out, and months later some separate coverage of a bill introduced in Congress to require official social media accounts to be archived which was given that nickname.