A different variant on research... when the means becomes the end... million dollar prize pools in League of Legends tournaments: "We’re distributing $1,000,000 cash to hundreds of community-organized Prize Events throughout Season Two."

http://competitive.na.leagueoflegends.com/competitive/season-2/introduction

I've read through a lot of research on the subject. Not enough of it teases out causality through good design. But I'll see if I can find some that does.