In Europe (at least in logic and/or philosophy) the dominant model of a conference involves: a few invited speakers, some contributed papers (acceptance is usually based on abstracts). Some conferences diverge from this model. Sometimes, there are no invited speakers (e.g. EetN 2013). Sometimes, full contributions are required and reviewed (e.g. EetN 2010, EetN 2011, EetN 2013, TiL XIV). Sometimes, there are no contributed papers (on purpose, I won't give any example) and the only speakers are those who were invited by the organizers. On the face of it, closed workshops/conferences are kinda cool: If you're the organizer: You don't have to prepare and distribute your CFP. You don't have to collect and manage the submissions. You don't have to find referees to review the submissions. You don't have to message the contributors with the results. Some of the speakers might later invite you to their closed event. If you're an invited ...