Comparing is in our human nature. One of the most popular topics about Surface around the web is predicting the amount of sales and compare that to Apple's iPad sales. Well, that's not a fair comparison. IPad is being sold in Apple's Stores around the world (395), Walmart (8970) and BestBuy (1150) for a total of more than 10500 stores. There are other companies selling the iPad but I'll just ignore them, with these 3 we have enough for our comparison.
Do you know how many stores Microsoft has around the World? 32. 31 in USA and 1 in Canada. Now you can see why is really unfair to compare Apple's sales against Microsoft's Sales at this point on time.
Lets do an easy and quick calculation, imagine that all these stores only sell one unit per day, after a month the whole total between all of them will end with 325965 iPad against 992 Surface RT!
Lets keep playing and guessing. If the rumors around the web are right and Microsoft will end these two months selling 500000 units, and that the experiment that I read where somebody checked for one day one of the Microsoft Store and did not see anyone coming out with a Surface is real. That means, that knowing that at 1 per day rate all the MS stores could have sold only around 2000 units, we can say that almost the whole 500000 have been sold by the online Store, this means around 8000 units per day!
That's why the rumor of Microsoft starting selling the Surface RT in other retail and online stores is that important.
We are talking about the potential of selling 1000 units per day in the retails stores of other companies to 10000 per day in their online Stores. Imagine BestBuy and Walmart online Stores selling per day the same as MS, 8000*3= 24000*31= 744000 units per month! And if the retails stores of Walmart and BestBuy just sell 1 unit every two days we are talking about 150000 unit's more per month (counting that Microsoft is thinking about selling the Surface in these two big companies).
After seeing all these numbers I believe that with this move Microsoft can sell easily around a million of units per month. Which is a decent number.