Apple will definitely grab some market share from the booming e-reader market, whose sales will grow 75 percent to 16.21 million units in 2011, according to Digitimes estimates. On the other hand, iPad's debut is expected to boost the whole market size of e-books.

The iPad is based on the iPhone operating system. The applications built for the iPhone will run on the iPad, providing users with access to over 140,000 existing applications.

"I want to own an iPad because I can transfer my purchased applications (from iTunes) easily from computers on it," said Joyce Mei, a 24-year-old young woman who has already has an 8GB iPod Touch and a 13-inch Macbook.

With the launch of iPad, Apple has completed the production chain from laptops (Macbook) to portable devices (iPad and iPod) to mobile phones (iPhone).

"We are the largest mobile device company in the world ? larger than Sony, bigger than Samsung, and, by revenue, even bigger than Nokia," said Jobs, who has changed the company name to Apple from Apple Computer.

Apple's rivals are numerous and notable: Nokia, Sony, Samsung and now Amazon. But none of those giants operates a successful online shop like iTunes Store.

In the dot-com era, the rule is: Content is king.

In my opinion, Apple is one of the best examples of companies taking advantage of "cloud computing," though it seldom discusses the concept directly during its media conferences.

Cloud computing is Internet-based development and use of computer technology. The term cloud is used as a metaphor for the Internet, based on the cloud drawing used to depict the Internet in computer network diagrams. Typical cloud computing providers deliver common business applications online, which are accessed from a Web browser, while the software and data are stored on servers.

As a result, Apple need not depend on hardware design innovation anymore. Instead, it helps partners and developers distribute content and application based on the revenue-sharing business model and qualified Apple-designed products. Through the process, consumers can easily access the services they want, and Apple gets income and market share.

The hardware design completely serves consumer demand and cloud computing, like iPad's large screen, long battery life and super mobility.

Some argue that iPad should feature camera and phone functions. I'm not sure I agree. Would you really want to call friends or take photos with a laptop-size gadget?