(This only changed recently. A few years ago, all cars featured variety in their ads. Now almost all cars are dedicated to a single type of ad, which means you encounter Dr. Zizmor less often.)
I thought about this and came up with a couple reasons. First, there are a lot more car spaces than platform spaces. Probably 500x as many car spaces. Maybe the MTA looked at their numbers and saw an individual car ad was costing more to manage than it was producing. So they started forcing advertisers to buy an entire car's worth of ads at a time.
Second: a single platform ad will have about the same effect as a whole car of car ads. People usually sit still in a subway car, but they walk along the platform when they get out. Everyone in a subway car will walk by a few platform ads on their way in and out, but within a car they will only see the ads in front of them.
And while the people are sitting down, the subway cars are moving through the stations. An ad on the subway platform will be seen by people in the facing car. So, to make sure a carload of people sees your ad, you either need to buy up the entire car's ads, or one or two of the platform ads facing that car.
I've also noticed that movies are only advertised on the platforms, and booze is only advertised in the cars. (TV shows are advertised in both places.) What's the pattern?

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Posted by Susie at Wed Oct 20 2010 00:21
Posted by Space Hobo at Wed Oct 20 2010 06:13
Posted by kirkjerk at Thu Oct 21 2010 09:36
Posted by Leonard at Thu Oct 21 2010 12:37