All good questions. I'll try to help - ADVERTISERS would likely desire that functionality, but we don't plan to monetize that way.. ancillary to qualifying humans for knowledge we also gain the ability to show the most relevant articles per subject (a timeless piece on Startup financing by Fred Wilson in "Venture Capital Models" or a post on Startups from Paul Graham in "bootstrapping"). All older posts that largely get covered up in the world of 'real time' that we have become so accustomed to in this age of twitter and google. Thus advertisers could... target by keyword/s in subjects/topics (like google ads). Credits per se aren't a currency for trade. They can only be acquired through reading/learning.