Things people sell cheaply to make money down the line

My sister was talking today about getting an iPhone but she said she was now leaning against it. She's thinking about getting a regular cell phone and an iPod Touch instead. I said I thought that was a great idea because it's not so much the base price of the iPhone that's so bad, but the service that goes with it. I find these things so fascinating (and brilliant), and kind of have an ongoing list in my head. Here it is:

iPhones (The $ are in the service - not that the base price isn't expensive, but they are really making their money in the service)
Razors (Companies OFTEN give these away free, or at least very cheaply, because the real money for them are in the zillon dollar replacement blades they sell)
Printers (Again, often very cheap because the money is in the ink cartridges)
Xbox (I don't know if this is true anymore, but Microsoft used to take a box on each unit they sold because they made their money in the software)

I just find these things so brilliant! Genius marketing plans. Just like the Chrysler $2.99 a gallon for 3 years on gas - best case (15 mpg and $5/gal gas) you're saving roughly $5000. Car companies give $5000 rebates all the time - so this isn't anything new or special, just a different spin. I should have gone into marketing.