With app numbers in the marketplace already rising over 3K getting your application noticed is more and more important. One of the features a lot of applications still miss is trial mode. Personally i would not consider buying an app unless i get the chance to preview it and i know this opinion is shared by a lot of users around the world.
Fortunately Microsoft provides an easy way of implementing trial mode and a lot of information on different implementations is available all over the web. Since people keep asking me how i implemented it i will cover it in this blogpost.