Our business model is a Freemium model whereby Authorea is free to use as long as you produce public content. You can write as many documents as you like on Authorea for free as long as you keep them "open". If you want to create private documents, you pay for private hosting. By using this model, we are encouraging authors to do "open research". Please note that Authorea does not have copyright on the content. All content produced is the ownership of authors. An author can delete, download, modify content at any point in time. So, in that sense, we are very different from traditional publishers (including PLOS, which is basically a traditional publisher). For the time being, we plan to keep charging scholarly authors, who pay because they are using a collaborative tool writing tool built exactly for them. We are getting increasing interest from institutions, departments, research labs who want to buy group licenses.