Basically I check this forum every few months.
I'll run through the threads check the votes then add the threads I feel have a majority of votes for yes.
Threads are then locked.
A locked thread means that the decision has been made to either enter the thread into the vault or not.
Criteria I look for in adding threads are, lots of votes, and a clear majority saying yes.
Polls with only a dozen or so votes, won't get added, and anything that's 60/40 or close to it, won't get added either.
So don't worry if your nominated thread hasn't been looked at for a while. It will in time.