Web & Digital Media
Why: The exponential growth in traffic on the Web is possible because of services that route data intelligently.
Key innovation: Its algorithms optimize online routes for content delivery.
Why: E-books are finally becoming a large, mainstream market.
Key innovation: Even as it seeded the e-book market with the Kindle, Amazon has made it easy for people to read e-books on other devices, such as the iPad.
Why: It still sets the agenda in Web search, even as it pushes the development of Android for mobile devices.
Key innovation: Its software development process remains relatively fast even as the company has gotten very big.
Why: Inexpensive video on demand, delivered over the Internet, undercuts cable and points the way to a likely future for TV.
Key innovation: Built demand for a streaming video service by including it free with DVD-by-mail subscriptions.
Why: Web applications must get faster and feel much more responsive to users if cloud computing is to keep growing.
Key innovation: Its technology efficiently routes traffic across the Internet and makes websites faster.
Why: Corporate decision-making gets smarter if it taps the insights of rank-and-file employees.
Key innovation: Private prediction markets let employees forecast the results of corporate choices.
Why: Social networking on the Web is becoming a powerful advertising medium and a platform for startups that offer add-on services.
Key innovation: Adapts quickly to shape its site into a medium that advertisers consistently want to use.
Why: By encouraging millions of people to sign up for quirky daily advertising e-mails, Groupon has created one of the fastest-growing revenue generators on the Web.
Key innovation: Offers local businesses a way to guarantee a return on their promotional budget, thereby tapping into a huge advertising pool that has eluded many Web companies.
Why: Augmented reality enhances the value of a mobile device, employing its camera and GPS and displaying information about the user's surroundings.
Key innovation: Its development platform lets businesses and advertisers add AR functions to their own apps.
Why: Now that the company has begun to make money from its large user base, a service that has woven its way into everyday life is more likely to stick around.
Key innovation: Its business model offers selected opportunities for advertisers while drawing income from deals that let search engines index its content.
Why: Web tools can help people respond to crises such as earthquakes and political protests.
Key innovation: Its open-source crowdsourcing tool overlays field reports on maps, providing critical and often life-saving data during emergencies.
Why: Companies are building businesses inside platforms like Facebook.
Key innovation: Its social games offer people a new way to interact.