The industry quickly followed suit.

Amazon now also has a wealth of online content in addition to the books the company started with and is increasingly using devices to get people buying it. Note the , for example. It also doesn't come as a surprise that Google may be to compete with Amazon and Apple.

And ever since people began walking around with Apple's white earbuds in place, the entire consumer electronics industry has reacted. Countless accessories have been made for the iPod line, including some .

Originally, the now ubiquitous entertainment device was a 5GB music player that only worked with the Mac operating system and used a FireWire connection instead of a USB cable to update songs and charge the battery. After many iterations, today the iPod line includes the iPod Classic, the touchscreen iPod touch, the iPod Nano and the tiny iPod Shuffle.

Millions of them have been sold worldwide.