I really don't like "fact-checking" articles like this which don't contain many useful facts, only pedantry. The first comment (by Kristen McLean from NPD BookScan) is much more interesting than the article itself:

>>>0.4% or 163 books sold 100,000 copies or more

>>>0.7% or 320 books sold between 50,000-99,999 copies

>>>2.2% or 1,015 books sold between 20,000-49,999 copies

>>>3.4% or 1,572 books sold between 10,000-19,999 copies

>>>5.5% or 2,518 books sold between 5,000-9,999 copies

>>>21.6% or 9,863 books sold between 1,000-4,999 copies

>>>51.4% or 23,419 sold between 12-999 copies

>>>14.7% or 6,701 books sold under 12 copies

So, ~66.1% or 2/3 of books in their dataset sell under a thousand copies.