Just to clarify, you don't have to wait until one book discussion is finished to start another book discussion. As we discussed earlier in this thread (I think U13 raised the question), we can have several discussion threads active simultaneously since this isn't a typical book club. What makes ours unique (and better, IMO) is that we are "fluid" in that we can have 3 or 4 (or 34) "clubs" going on at the same time. We can join whichever book discussions we choose. Someone who may not want to read "Choir Director" may be interested in going through the Proverbs or one of Paul's epistles. Someone who doesn't want to do a Bible book may want to join a different discussion.
There's nothing stopping us/you from starting a new "club" whenever anyone expresses interest in joining you. Where 2 or 3 are gathered together...