[3] In July 1999, the NPD Group and GfK co-purchased the entirety of market research firm Intelect ASW, a company focused according to The New York Times on "the consumer electronics, information technology and appliance industries.

Those who purchased TRST's data, which NPD repackaged without extrapolation, were discouraged from republishing the raw figures.

[9] In October 2021, NPD entered intro an agreement to be acquired by private equity firm Hellman & Friedman.

[10] NPD serves industries in the United States, Australia, Belgium, Brazil, Canada, China, France, Germany, Italy, Japan, Mexico, the Netherlands, New Zealand, Russia, South Korea, Spain, Sweden, Turkey, the United Kingdom.

[13] NIQ (formed from divestiture of consumer intelligence business of Nielsen Holdings in 2021) still operate their book services outside of the U.S., including BookScan in the UK, Ireland, Australia, New Zealand, India, South Africa, Italy, Spain, Brazil and Mexico.