The (successful) Apple TV.

Who said the Apple TV was just a hobby

Apple announced today that unit sales of its tiny set-top box are expected to reach 1 million by the end of this week.

The Apple TV, which launched in September, is one-quarter the size of its predecessor, and allows users to rent and stream television shows and movies from iTunes on their televisions. The set-top box also features access to Netflix, podcasts, and Flickr. Users can stream music content from their computers, and use AirPlay to send multimedia content from their iOS-based devices to the Apple TV. It retails for $99.

But that success didn't come overnight. Quite the contrary--Apple TV's trek to get to this point has been one for the ages.

The first Apple TV launched in 2007 as a "hobby" for entertainment-seekers. Unlike the latest Apple TV, the first version of the device featured onboard storage, allowing users to store their entire iTunes library content on the device. However, over the next three years, Apple offered few updates to the device, allowing it to languish on store shelves.

At a press event in September, Apple CEO Steve Jobs said that his company believed consumers didn't want to store content on their set-top boxes, and instead preferred to stream content. The result was the latest Apple TV, which Jobs said, was no longer the "hobby" its predecessor was.

With the company expecting to have sold 1 million units of the new Apple TV by the end of the week, it certainly seems that way. It also seems that Apple is throwing down the gauntlet in the living room against the countless competitors it faces.

Roku's XDS set-top box, for example, boasts a $100 price tag, and includes a slew of streaming options, including Hulu Plus, Netflix, and Pandora. Others include the recently released Boxee Box and the Logitech Revue, which offers Google TV software.

But Apple didn't limit its chest-thumping to the set-top box market. The company also announced today that iTunes customers are "renting and purchasing over 400,000 TV episodes and over 150,000 movies per day."