Let's say that Igor is approached by the local food bank. If he does this, they guarantee they'll be able to get regular announcements on the three top local radio stations. He assumes all his full-price people will bring a can of food. Igor now expects a sell-out, and can concentrate on doing improv. For those of you doing your math, you'll notice Igor didn't sell out, he sold 254 seats out of a potential 296.
Projections are always wrong, and usually high.
There are variables you can never take into account, like weather, competing entertainment, and whim. If you have produced improv shows, you know how rosy this projection is. What I've tried to show here is the thought process you should go through when doing the numbers for your shows, not tell you what you should expect or how you should measure your success. Igor was able to execute all his ideas, and in this story, all his ideas worked to some extent. From long experience, it just ain't so in the real world, but by using these systems, you'll at least have an edge.