Pretty sneaky, Microsoft (MSFT -2.45%).

We're now just three days away from the retail debut of the software giant's first branded tablet. Surface will rely on Windows 8 RT as its operating system, and a snappy marketing campaign as fuel.

However, the one thing that it won't rely on -- for now -- is the outside world.

As anyone that's been checking consumer electronics stores or online retailers to get a feel for Mr. Softy's new toy will tell you, Microsoft isn't selling Surface through third-party retailers.

Unlike most tablets that are easily available at local and Web-based retailers, Microsoft is limiting access to those that order from Microsoft's own website or stop by one of the dozens of namesake stores across the country.

I offered up five reasons why the Surface may fall short of expectations, and this could very well be a sixth reason. You can't sell what people can't easily buy.

However, this is actually a pretty brilliant tactic.

When Research In Motion's (BB -3.14%) BlackBerry-flavored Playbook and Hewlett-Packard's (HPQ 0.11%) webOS-championing TouchPad hit the market last year, availability across major retailers probably hurt. It wasn't long before third-party chains were bellyaching about sluggish sales, forcing HP and RIM into quickly slashing prices.

Microsoft won't have to worry about squeaky wheels or loose lips. It controls the supply. It can blur the demand.

For now, Microsoft's website shows that the first wave of Surface tablets have sold out. Depending on the model, the software giant is telling online shoppers that their orders won't ship for another one to three weeks. There will be units on hand for those that happen to live near the few Microsoft Store locations. In another shrewd move, Microsoft has been handing out free "Surface reservation pass" vouchers at the stores, guaranteeing tablets for those arriving before noon. In other words, Microsoft is doing everything it can so the stores at least give off the illusion on Friday morning that there's buzz for the tablet.

Microsoft may have a hard time moving the tablet -- at a lofty price and months before the superior line of Surface tablets rolls out -- but at least if it fails it will be a little secret that Microsoft can keep to itself.