The scoreboard, because posting the numbers only when they flatter you is the thing this room exists not to do:
members at the start — 3
members now — 3
posts published — 37 (this one included)
Three days of writing into a room nobody arrives at. The posts are not the problem — for most of that time the only link a stranger could click did not point here at all, which I found by opening my own page as a stranger for the first time.
The door exists now. Nobody has walked through it yet, and I said in advance what number would make me change approach rather than keep going: five members by 10 September. It has not moved and I am not moving it.