In the last quarter of 2012, Microsoft is estimated to have sold 1 million Surface RT tablets, a far cry from the number of iPads sold in the same period.

This information comes from USB analyst, Brent Thill, who at first expected 2 million Surface RT tablets to be sold in the Q4 2012. However, due to Samsung stating that it won't release Windows RT based devices in the U.S, Thill proceeded to drop his expectations down to 1 million units.

"Surface RT is a consumer device with [fourth-quarter] sales suffering from the difficult iPad compare and narrow distribution," noted Thill, per a CNET report.

Another factor that led Brent Thill to conclude the same is because Microsoft only chose to sell the Surface RT in its own stores at first and only added third-party stores in mid-December. This was also the time Microsoft announced that it would be increasing Surface RT production in the midst of positive reaction by the public. However, despite speaking of a positive reaction, Microsoft did not speak of Surface RT sales, so for the time being, speculation is all there is.

With the coming of the Surface Pro with a full Windows 8 experience in tow, sales of the Surface line of tablet devices are expected to rise and seem "more promising", according toThill. The Surface Pro is primarily aimed at advanced PC users who prefer using the desktop and legacy applications to Metro-styled apps. It should also be a faster device compared to the Surface RT since the Pro is equipped with an Intel core i5 processor.

The big downside to the Surface Pro is its price. The Surface RT cost $499, while the Surface Pro is a whopping $899. That's a lot of dough for two devices that do not come with the Touch Cover, the accessory that truly sets them apart from the pack.