I am in the process of rolling this method out. I started with a short-form scholarship offer paying $4.50 per lead. I have only done one day of dropping flyers so far, where I went at 7AM and blanketed several classrooms in a building before classes started for the day. I will tell you that as of three days after, I almost perfectly broke even on the cost of flyers. With further tweaking (flyer design, different offers, better locations as I now believe classroom dropping is suboptimal, lots of other ideas I don't want to share yet) I believe I could get this up to twice or maybe even three times as much profit on the same number of flyers. I don't see it going much higher barring a mega breakthrough.
Obviously, this is not something that will make anyone rich on its own, but my long-term plan is to develop a workable model that is easy to outsource (and worth it, commission-based, for the poor kid you hire to do the dropping). I'll report back with more as I further refine.