I’m not sure you’re aware of quite how many things get “backed into CPMs” at larger publishers/advertising companies… for a Denton specific example, check out this craziness:
it makes sense to me that as Boing Boing would be very familiar with the publisher side of “CPM” as used in display. Certainly Abramson could have given a better introduction to CPMs. But this doesn’t read as a gaffe like you say. The other criticisms of the book are much more potent. My two cents as someone who works with revenue at a media company.