The iPhone will be a major achievement for Apple, a company that has never dabbled in such a device before. Both the hardware and the software will show just how good Apple is. But the iPhone will test not only Apple's ability to make a great new product, but also the company's ability to sell it.

Both the software and the hardware for the first iPhone have long been set in stone, but the support for it is still in the making, as are the preparations for selling it. This will be the biggest challenge that Apple faces in retail since the opening of the first two Apple Stores in 2001. Consumer expectations are very high, so high that Apple needs to deliver perfection or leave customers with a lackluster feeling.
The company is well aware of this, and jobs has already stated that the Apple stores will be quite crazy during the iPhone release. All aspects need to be covered, from marketing to sales, training and support.

There have already been reports that Apple stores are being fitted with cellular repeaters to insure perfect reception for demo iPhones, so potential customers will have a flawless experience.
Apple has also been hiring and training for an iPhone telephone support team based in Sacramento, but it will invariably be the Geniuses in Apple Stores that will be seen as the true support team for the iPhone. People will be taking the bulk of their iPhone technical support and questions to the Apple Stores out of habit and because most prefer talking in-person.

Another rumor that is going around is that iPhone sales will include a method of streamlining the traditionally long purchase and registration process. This goes hand in hand with rumors of iPhone activation done through iTunes for phones bought over the Internet. If true, this will make the process of buying an iPhone much easier and faster.