Yes! The big example I can think of is Lani Sarem’s Handbook for Mortals, which debuted at #1 on the NYT Best Seller List despite not being available for purchase on Amazon or Barnes & Noble, and having only two reviews. It knocked Angie Thomas’s The Hate U Give out of the top spot and caused quite a stir when people realized that Sarem bought her way onto the list by pre-ordering 18,000 copies of her own book (in batches of 29, so it wouldn’t trigger a “mass purchase”). Here’s a Guardian article on that case: https://www.theguardian.com/books/2017/aug/25/handbook-for-mortals-by-lani-sarem-pulled-from-nyt-bestsellers-list

But it definitely happens on a smaller scale all the time, which is why orders of 30 or more books are considered differently (ie, as stock for stores) rather than being reported as individual sales. It’s supposed to be a failsafe for frauds like this, but Sarem was one who almost got away with it due to her ‘small-bulk’ orders. (She’s also a nepo: her cousin was a member of N’Sync.)