When you earn views, they work as a virtual currency that you can then spend on upgrades for your room, which in turn leads to still more views. This is a cycle that you definitely want to have working in your favor. New items can improve the number of views per video, while others improve both views and subscribers and even your skills in a particular area. Skills are important because when you make new videos related to that skill in the future, they'll perform better due to your existing boost.