> Signaling, however, grows stronger the larger the out-group is – as long as the out-group knows about the in-group. This is why luxury car manufacturers deliberately extend their advertising campaigns to people who will never be able to afford their cars: they are increasing the size of the out-group by educating people about the in-group.

I assumed that car advertisements were only targeted at those who might possibly buy the car. I didn't think that car advertisements could be "educational material" about how cool your friend/acquaintance is for driving this car.