Deriving the Most Profits from "Free" Space

I have been spending my past week in Hong Kong, finally having enough time to spare to see my hometown. 

It has taught me plenty of things about:

• Logistics: try taking transit or taxis here, it's a whole new experience - if you don't jump out quick enough the bus might close its door on you - it has happened before, look it up in the news; 

• Economics: that they might be wrong about there being some sort of recession, since there are approximately 500 million people shopping at 11pm at night - the stores don't close here!
• Efficiency: The elevator, MTR, restaurant, or just ANY space in general can always fit more people.  I saw people literally pour out of the MTR cars and elevators.
  
• Profit Maximization: Taking a look at the MTR stations in Hong Kong, they use every available space for advertisements.  Walls beside the elevators going up, ceilings, round pillars...everywhere you look there's an ad.  This generates a lot of profit for the MTR stations, and whoever built our skytrain stations out in Vancouver should do the same.  Olympics are coming up, tons of people will be taking the skytrain so why not put ads in the stations?  I've taken the skytrain a couple times and it's quite boring standing there waiting; give me something to look at, that will make me spend more, buy stuff and help the economy (this is the Florence economy stimulus plan..haha).

I think it's because space is so precious in Asia that we make the best use of it; scarcity stirs creativity.  North America can seriously do better maximizing its use of free space.