I had an interesting discussion today with an international student about the phrase "New York Times bestseller." In Spain, he said, publishers simply write "sold 400,000 copies" (or whatever number) on the front cover of a book to show that it has done well. I've never give much thought to why people go specifically by the NYT list... I suppose it's because the Times is one of the most followed newspapers in the country (perhaps the Post is too political and the Journal is too focused on business?) and because the publishing industry is strongest in New York.
One topic we've covered a bit in the last few days is the NYT children's bestseller list. It actually came about because of Harry Potter, which took up three or four spots on the regular list during its heyday. People were ticked that these books took up so many spots, leaving little room for other "adult" bestsellers. With HP and Twilight both still selling strongly, the NYT went even further, creating a third list of only bestselling children's series to accomodate them and leave room for other books to rise.
While the two phenomena still techinically get props for their success, this brings up an interesting conundrum of comparison. How does one know if Twilight is outselling the #1 title on either the children's list or the adult list? Or if Harry Potter and the Sorcerer's Stone, specifically, is still making waves years after its debut? There are other lists in Publisher's Weekly and the like, but not in places nearly as widely available to the public as the Times.