We compare data storage from Apple, Amazon, and more

By Jon Chase
Updated July 01, 2011 at 04:00 AM EDT

Best Buy joined the cloud crowd last week, announcing the soft launch of its Music Cloud service. And as with so many of the entrants in this relatively new but crowded market — including heavyweights like Amazon and Google — the forecast is looking rather stormy, thanks to impending competition from Apple’s eagerly awaited iCloud service (due this fall).

For the uninitiated, cloud storage services let consumers upload files — music, video, photos, ebooks, whatever — from a PC, smartphone, or tablet to far-flung servers that can be accessed anywhere. The biggest appeal for most users is the ability to store, access, and stream their entire music collection. (Think of it as a jukebox in the sky.) So what gives iCloud an edge over Music Cloud, Amazon’s Cloud Drive, or Google’s Music Beta? Those services haven’t locked down licensing agreements from the major record labels, meaning that new users will have to manually upload their music library to their digital ”locker” in the ether, a process that can take days or even weeks. But Apple’s iTunes Match software ($25 a year) will scan your song library and then upload only the songs that don’t already exist in Apple’s own ginormous 18-million-strong song catalog, making the entire process near-instantaneous.

In fact, the biggest threat to iCloud isn’t a cloud service at all. It’s beloved Pandora Radio (which has raked in a couple hundred million bucks since its June IPO). While iCloud and its competitors allow subscribers to access their own music on the go, Pandora offers up all of its music collection (about a million songs and growing) instantly and free. And that price tag may just be enough to give it an edge.