Pro Plan is big mistake
You are making a huge mistake here. Many people came over to SA after the demise of Yahoo Finance Message Boards, looking for a place to have free exchange of dialogue. While SA wasn’t perfect, some of the amateur articles were pretty good, but more importantly, there was often an active dialogue in the comment section. Unfortunately these comments would die down within a few days or if lucky, a few weeks, so it couldn’t mirror the value of YFMB, which had open running dialogue on each stock (it still does, but it is such a poor system that most don’t use it anymore). The beauty of YFMB and of SA was that it offered a free exchange for the everyday investor who couldn’t afford to buy high end research. In fact, many felt that the dialogue among many investors is much more valuable. What will happen now with the move to Pro is that the majority of your readers will not pay up for Pro, and you will lose the most valuable part of your site, the article comments. Case in point: I subscribed to a Marketplace author, and while I enjoyed his articles, there were virtually NO comments, which rendered the overall experience unworthy of a fee. You know why there were no comments? Because no one is willing to pay a fee for amateur articles. You need to understand who your readership is, and stick with an advertising model, or else you will price yourself into irrelevance. Don’t make this mistake.