My first approach to this was to do a SWOT analysis on competing sites, primarily DocStoc, Prezi & Scribd. Although SlideShare was the most popular among them, the competitors already had some sort of Premium features for paid users. Unfortunately, they hardly had any interesting features worth paying for. So I started approaching the power users to get an insight on what they like and what they don’t or would like to change/improve. And that went really well. Our tool of choice was KissInsights, which made it really easy to speak to users active on the site. The findings were very eye-opening. In a few weeks, we already had a list of features people were willing to pay for. We started testing them with a handful of users (who we knew were the most popular uploaders).