Nokia has gone to great lengths to make it easy for developers to create promotional materials for their Windows Phone apps via their Marketing in a Box offering, including marketing videos, banners, facebook page and website among others.Steps to make your own promotional marketing video
On the next page:
On the next page, you can choose the words that get displayed during the video, choose the adjectives that best describe your app’s user experience.
You’ll be brought to the preview page. If you want to change something, you can go back and alter your choices.
You’re almost done, the next steps involve signing into your YouTube account and wait for the video’s full rendering and auto-upload to your online profile. Congratulations, you now have a great looking video to promote your app.