The NYT has a remarkable series of interactive maps for 12 metropolitan areas showing Netflix DVD rentals by movie by by zip code. For example, in LA, Woody Allen's Oscar winner Vicky Cristina Barcelona is #1 in 90210 (Beverly Hills), but isn't even in the top 50 for most of Socal away from the Hollywood Hills and the coast. One exception is the Montebello-Whittier area, which is the most upscale Mexican-American region, whose residents might be attracted to a movie that's partly in Spanish and stars Penelope Cruz and Javier Bardem, big stars from Spain.
A couple of methodological biases to note: Netflix rentals by mail are driven by grown-ups, not by teenagers who like going to movies at the mall. Also, Netflix is usually seen as more upscale in its customer base than renting by mail from Blockbuster. (Stuff White People Like has a chapter on Netflix.)
Thus, The Dark Knight doesn't do particularly well on Netflix because most of the people who wanted to see it went out and saw it in the theatres. And then, if they really liked it, they bought the DVD rather than rented it. The type of movies that do well on these Netflix maps tend to be Oscar-bait movies that were only moderate hits in theatres, such as Brad Pitt's Benjamin Button and Angelina Jolie and Clint Eastwood's Changeling. You get the feeling of dutifulness looking through the maps — people ordering Important Movies that they feel guilty that they weren't enthused enough to see in first release.
Mad Men, unsurprisingly, is only popular in the entertainment industry zip codes of LA.
One interesting thing is that you can frequently see the black neighborhoods in west south central LA — check out the Tyler Perry movies for the map of black LA. The black neighborhoods tend to either love movies (if they have black stars) or ignore them.
The huge Hispanic neighborhoods to the east, however, aren't as distinctive in their tastes. There are almost no movies in Netflix's top 100 that have Latin American stars, so they mostly seem to take whatever popcorn movie Hollywood is handing out (while avoiding indie stuff like Rachel Getting Married, with its SWPL multiculti obsessions.)
The maps can be oddly centered — the LA map, for example, includes places like Placentia, but not Malibu and Santa Monica.