It's very useful, as Dropbox users can attest.

Copy files to Google Drive faster in Windows 7.

Make Google Drive your default documents folder.

'We want you to think of this as the center of your Google apps experience.' 'You can take all your data, regardless of which device you're on, and make it seamlessly available to you,' said Sundar Pichai, senior vice president of Google's Chrome and Apps projects. On my Android tablet, though, you'll need a network connection to actually see the files behind the file names.

If you copy or save a new file to the folder, or if you upload one to the Google Drive site online, the technology automatically replicates it at all other Google Drive locations. That device gets a special Google Drive folder that synchronizes its files with a mirror stored online. Google Drive, at its core, looks a lot like Dropbox: you install software on a device running Windows, Mac OS X, Android, and 'in coming weeks,' iOS.

That's a pretty big philosophical shift for Google.

Second, beyond a basic free level, ordinary consumers will pay to use Google Drive - not much, but enough to make them into customers, not just users of an advertising-subsidized service.

First, Google's service goes well beyond rivals because of integration with Google Docs, Google+, Gmail, and other services.

Google is set today to open Google Drive, a service to store files online and share them among various computing devices that turns out to be a lot more important than you might think.

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