I'm intimately familiar with the LAF/Nike agreement and Nike isn't making a dime. They provided a $1M initial gift, absorbed the cost of the marketing for the campaign, and gave the LAF the first 5 million bands for free to sell on:
http://store.laf.org. The LAF is the only entity benefitting from the popularity of these bands (aside from a few greedy #$% on ebay). Neither Nike nor Lance are profiting from their sale. To some this may be a fashion trend, but for many of the 10 million cancer survivors in the US alone, it is a symbol of hope, support, and recognition of their battle.