They may have done, but I don't like them for their real-time-ness ! Most modelling questions I answer here (for example) would get a far inferior answer in real time than they do after much-considered thought and well-prepared diagrams / videos / other assets there is time for in a forum. Real time means you tend to get the first idea out of people's heads, and no1 has time to try stuff first... though I appreciate the corollary of having lots of brains answering in quick succession, and the wisdom of crowds, such as it is !
Also the amount of revisions and edits I do to posts to improve them is all wasted / unavailable in a real time format, hence why I find forums the perfect environment to help in...
CBR