One could do the "jump-in" method with caveat that players only need post profiles for their characters or some other similar minor criteria but as one imagines, it is not always the case where users would read it. If one wants to get started right away, I agree with the motion that saying "Feel free to post once approved." is the best way to get it started. If anything the sole reason that people seem to wish to a have a number of players first is so that the plot can begin right away but seldom would it be that prevents characters from milling about on their own accord then being called to the plot. From my past experiences, long, long before the Roleplayer Guild, that was the norm and I am of the stance it could apply here just as well if one desired.