That was me Rag.
You referred to Coogan's book as a "best seller" as if one of the reviewers had so described it.
I have always described Coogan's work as populist. It outsells the work of actual, academic hisrorians mainly by appealing to anti British prejudice.

The figure of 8000 was given in the review, which also said that sales of all 1916 books had been disappointing.