Thanks for the suggestions.
With the vagaries of sales especially around the holidays, it is difficult to tell. Historically, my sales have gone up pretty sharply around the 1st of January. I am not in KU. When I was, that really made analyzing results impossible.
I never mind not making money on an AMS ad as long as I do not lose money on it. I have a very high sell through on all my series, so all I ask of it is that it feeds readers into the series.
I am skeptical that that ad is doing that in spite of feeling okay about the keywords. They are providing the clicks. That is not my best selling series, but it has decent sales so I am puzzled. I am going to give the ad another week and see how it looks then.
ETA: The AMS dashboard.

Yes, it is notorious. I tend to take its word on clicks because otherwise I don't even have a starting point for analyzing results. I know we have no
reason to trust the report on clicks, but I think otherwise I might simply go nuts (if I'm not already).