Unfortunately, that free 1 year subscription comes with a catch. You have to bring your iPad on to a Microsoft Store, and you have to be one of the first 50 iPad owners to show up at that location.
I don't know about you, but that's going to present a problem for this blogger; the closest Microsoft Store is about an hour away. Given the price of gas and the value I put on my time, the $84 that this freebie would save just isn't worth the hassle. (And it's for an app I wouldn't use much, anyway.)
The offer is good through Sunday, so if this sounds like a good deal to you then check the MS Store website for a local store. There are 60 odd stores in the US and Canada.
And if you're still on the fence as to whether the subscription is a good value, here's a chart which lays out the features found in the free app vs the paid subscription. In short, creating, editing, and saving documents requires the subscription: