BIG SPLASH: In the 10 years since its inception, Apple's iTunes has changed how people buy music and access entertainment. It's not only music's biggest retailer, it also dominates the digital video market. Its apps are the most profitable, it has expanded to books and magazines, and it is now available in 119 countries.
SUCCESS IN MUSIC DECLINE: While digital music sales rise, album sales have decreased and the music industry's profits have continued to drop over the decade.
WHAT'S NEXT: Can it continue to dominate? With competition from Amazon, Netflix, Spotify and others, iTunes will likely need to reinvent itself to remain at the top of digital entertainment.