It happened to me once that I bought a software and didn’t meet my expectations. So trailware should be good.
Microsoft will offer a trial option of whatever app you’re going to buy. Which means, rather than buying the app and being disappointed due to lack of satisfaction, you can poke around with it before buying it.
I wonder how would it be like… I mean, I don’t want to write another version of my apps with limited features -_-;