Many bronze badges are awarded for just for using features of the site. This is a simple and efficient way to advertise features.
One feature that took me (and probably also others) a while to find was the filter option on the Close Votes queue. This feature is extremely useful, an therefore we should make sure that everyone knows about it.
So, there should be a bronze badge for using the filter on the Close Votes review queue.
Even if you introduce a badge, how would the user know that the badge exists for using that particular option?- because users look for badges. They will see a badge name in the badge list and say "what's this", and they will find the feature. It works day in and day out on this site.
100 x 40 = 4000reviews a day, 500-800 questions off the queue. 200 regular reviewers would make 1000-1500 questions off the queue a day, 3-4 months to drain 110K that are there now, go figure. Not bad for a marketing pitch huh?