Nike Inc (NYSE: NKE) made waves last month when it said it would begin selling on Amazon.com (NASDAQ: AMZN) for the first time ever, but the sportswear giant made another announcement that may be more telling about the future of e-commerce. As the Swoosh aims to branch out its online relationships, it also said it would make some products available on Instagram, the popular Facebook (NASDAQ: FB)-owned photo-sharing app.