But it's about to add a booster rocket.
According to several analysts, Apple is working on a TV-set device that could disrupt the TV set industry much as its other devices have done in their industries.
This new device - to simplify, let's call it the "iTV" - is not to be confused with the existing Apple TV, a set-top box that allows users to access digital content from the Internet on their televisions.
We're talking about a full-fledged television, albeit one with Apple's special touch. And that is what will push Apple stock even further skyward.
In a note to clients last week, Piper Jaffray analyst Gene Munster made a case that Apple is already building the iTV, which he expects could add billions of dollars to the Cupertino, CA company's top line.
"We believe that of the estimated 220 million flat panel TVs sold in 2012, 48% or 106 million units will be internet-connected, of which Apple could sell 1.4 million units," Munster wrote. "We believe an Apple Television could add $2.5 billion or 2% to revenue in 2012, $4.0 billion or 3% in 2013 and $6.0 billion in 2014."
Munster said he had met with Asian component suppliers that said they knew of prototypes of the new Apple device, and that the company had filed several patents for television interfaces.
But the definitive piece of evidence is a quote from Steve Jobs biographer Walter Isaacson's just-released book in which Jobs makes it clear that an iTV was the company's next major project.
"I'd like to create an integrated television set that is completely easy to use," Jobs said. "It would be seamlessly synced with all of your devices and with iCloud. It will have the simplest user interface you could imagine. I finally cracked it."
That "simplest user interface" is the key to why an iTV would be such a game-changer.
Tomorrow's TVThe iTV will not use a remote of any kind. It will be voice-controlled, using the same Siri technology Apple introduced earlier this month with the iPhone 4S.
"It's the stuff of science fiction," writes Nick Bilton in The New York Times. "You sit on your couch and rather than fumble with several remotes or use hand gestures, you simply talk: "Put on the last episode of Gossip Girl.' "Play the local news headlines.' "Play some Coldplay musicvideos.' Siri does the rest."
The iTV was waiting for Siri - technology that allows people to simply tell their television what they want to watch, whether it comes from the Internet or from a programming provider like Comcast Corp. (Nasdaq: CMCSA) or DIRECTV (Nasdaq: DTV).