The Nook e-reading app could also bolster Microsoft's efforts to establish a digital storefront to market apps, e-books and other content to go along with Windows 8, which is critical for the company's plans to enter the tablet market.

WSJ: Microsoft to Invest in Barnes & Noble's Nook

The Storefront Social app lets you display and sell merchandise from your e-commerce site at your Facebook profile.

FORBES: How To Make Facebook Work For Your Business

Threadless, the T-shirt e-commerce site and community of artists who design them, is looking at the storefront option as well.

FORBES: Will Amazon Get Physical?

Hunting for an e-bike, I ended up at a string of shops near the Tsinghua campus, where each storefront offered a competing range of prices and styles to a clientele dominated by students and young families.

NEWYORKER: Green Giant