Here are the raw results of my international BookBub earlier this week: about 200 more sales than last month's, and so far a handful of full price sales of other titles. Just a sprinkling, not an avalanche.
As far as I can tell, the true international sales were 100 over BookBub's average. I am not well versed on the exact dollar figures involved at all the various stores, so I'm merely guessing that this ad will earn a profit of maybe $70-$100 more than the first one did. Canadian readers were getting a super deal and bought heavily.
The ad stack winner was eReader IQ, which brought in 64 sales before the BookBub ad and only cost $10. BookDoggy ($20), FKBT ($30), and my newsletter ($7 per month, paid annually) each accounted for far fewer sales.
I expect to get a letter from Bookbub next week urging me to submit another title, and I will. I have one more women's fiction title that should work for the same audience.
Paying close attention to this was a good distraction during my last bit of self-imposed quarantine.