This is how (Score -1, Flamebait)

1. Apple already made premium profit on the hardware when the iPoop or iPhony was purchased by the slave, er, user.

2.Then Apple profitted by forcing users to buy the data - music, software, etc. - via Apple's online store, from which Apple profits.

3. Then users pay Apple to have a technician - who makes a low hourly wage - spend 15 minutes at most replacing the old battery with a newer one.

Now do the math:

  $86 per customer
-$35 est. max. cost of new battery

$51 Subtotal per customer
    4 Minimum customers per hour for replacement

$204 Subtotal per hour per technician
$-14 Labor cost (est. max.) per hour per technician

$190 Profit after labor and battery hardware costs
x 11 Hours of business outside of Sunday (most US locations)

$2,090 profit per day per technician

Of course, this assumes that a single technician only does this work for a complete shift. Multiply this by the number of technicians at a single location, and then multiply this by the number of locations, and it is plain to see that there is profit.