I recently came across a great interface and behavior in windows 8.1. If you implement ISupportIncrementalLoading on your bound property then bind up to a gridview you’ll get infinite scrolling for free.

Below is an example from my HypeMix app where I pull in more tracks and add more to that list as the user scrolls, hopefully useful to others.

[gist https://gist.github.com/lawrencegripper/9396993]