Google is reportedly planning on selling Chrome OS devices to customers using a subscription-based model. The search giant will first target Gmail users, though it's not clear if this refers to mainstream users or Google Apps premier customers.

Google plans to make the notebooks available for $10 to $20 a month per user, and will provide hardware refreshes as they are released as part of the package. The company will also replace faulty hardware for the life of the subscription, according to Neowin.

Google will also make the devices available for a one time payment, and will likely partner with retailers and carriers to do so. A price point has not been finalized, though devices in the US could cost between $250 and $600.

Since last year, Chrome notebooks from Acer and Samsung have been expected to arrive in the first half of 2011, and the most recent rumors say that Google will ship them in time for Q2 2011, possibly in June or July.

Chrome OS will only ship on specific hardware following deals struck between Google and the manufacturers. Chromium OS (the open source development version of Chrome OS) will be available as a disk image so that enthusiasts can put Chrome OS on any machine they please, though this won't get the same support from Google.

Chrome OS differentiates itself from Android by targeting devices with physical keyboards. Google's thinking is that many people already spend all their time in a browser, and that building an OS that is essentially a browser will make computers faster, simpler, and more secure.