1. A computer-implemented method of automatically extracting previously unknown topics from questions submitted to an online consultation system, each question having been posted by a user to one of a variety of subject matter segments to be answered by a subject matter expert, the computer-implemented method comprising using at least one processor to: for each posted question in a database of questions posted to the online consultation system: perform linguistic analysis to break down the question into component parts and extracts candidate topics, wherein the candidate topics are words and phrases that include semantic meaning, and wherein each posted question is relates to a subject matter segment; and for a desired subject matter segment: count the frequency of occurrence of each candidate topic within the subject matter segment; select the candidate topics whose frequency of occurrence within the subject matter segment is above a first and second popularity threshold; score each selected candidate topic with an affinity score, wherein the affinity score quantifies the affinity of each candidate topic to the subject matter segment; and identify the selected candidate topics with an affinity score above a third threshold as the best topics for the subject matter segment.