Your not going to see an overnight migration of listing count jump. New sellers are learning the ropes at other sites, Getting things listed.
What I have noticed was that Plunderhere had over 230 new sign ups since the first of the month. And I'm still migrating feedback from them. We have already beat May which had 203 new sign ups.
And there has been about a 2000 item increase. Remember also,
PSU only records auction count, not store inventories.