While Google's been working feverishly to build out its Play Store, bringing it to other countries and expanding its offerings, the company's music store has been lacking one crucial feature that its competitors have: library matching. Where Amazon and iTunes can scan your current collection and add the songs to your online storage, Google has, until recently, required users to upload every individual track manually. A long and tedious process. In mid-November, the scan and match feature came out for Europe, and today it arrives for US residents.
Where Google differs from Amazon and iTunes, however, is that this scanning and matching service will be entirely free. The other companies charge $25 per year for this feature. while, on the whole, it might not seem like much (it's a little over $2 a month), it can be difficult to understand why you have to pay to upload music you already own.
The reason for that, of course, is because the record labels are choosing not to verify your uploads. The way they see it, these digital locker services could be used to legitimize piracy. Especially since you'll be able to download your songs again from Google later on, and even have high-quality versions streamed from anywhere, if you didn't pay for those tracks to begin with, this makes them legitimate copies. The extra cash flow for scanning and matching is an appeasement tax. They get their money and, in return, won't be sticklers about proving you're not a dirty thief.
According to AllThingsD's sources, Google has opted to simply pay the record labels up front to cover the costs of this service, rather than being charged per user. If this is true, then it's a nice move by the search giant at least, since the company is essentially swallowing the cost of the scan and match feature, but it's no doubt doing this to make Play Music more attractive and to convince more customers to buy music. iTunes is a mainstay in the industry and Amazon's MP3 store has always been a close second. Google has a lot more to gain by attracting new users.
In any case, for those wondering on the details of how Google's scan and match works, your original files can't be uploaded unless the server is unable to find your tracks. If the songs it finds on your machine are of a low bitrate, then that's the best you'll be able to download later. Google won't exchange your 96kbps file for a 320kbps one. It will, however, stream to you at a higher quality.
So, if you haven't already gotten around to uploading your music library, now's the best time to do it!
Update: To clarify some concerns that people are having over re-uploading their collections in order to get the high quality streams, don't worry. You won't have to. Per Google's help files:
"If you’re a longtime Google Play Music user, you don’t need to re-upload your files to have them matched. In the next few months, we'll automatically match what we can of your existing library."
So, sit tight and don't panic.