If you've been holding off purchasing a Microsoft Surface unit because the keyboard is a separate cost (like that's the only factor), you can now move forward with your plans.
Microsoft is offering a free Touch Cover ($79 value) with the purchase of any Surface model (except, it seems, the Surface 2 LTE). The deal starts today and ends on Saturday, March 29, 2014.
Related: Surface Pro Disappears from Microsoft Online Store
Of course, this is the Touch Cover. Adding a Touch Cover to a regular Surface RT or Surface 2, is a good choice considering those models are generally used just as tablets. Adding a Touch Cover to a Surface Pro series is unimaginable, in my opinion. Personally, I'd go ahead and splurge for the Type Cover, as it totally changes and improves the overall experience.
Check out the deal here: Get a free Touch Cover with any Surface
