[briandear]

> Institutional, special interest, group or bulk purchases, if and when they are included, are at the discretion of The New York Times Best-Seller List Desk editors based on standards for inclusion that encompass proprietary vetting and audit protocols, corroborative reporting and other statistical determinations.

So basically, they use editorial discretion when ranking bulk sales. Which means they are prone to exclude books they don’t like and include books they do like. Excluding some bulk sales but not others isn’t objective. Institutional and bulk sales should all be excluded from the counts.