Hi, Oliver here (the report's author). Actually, we specifically stayed away from contacting JRebel users simply to avoid any additional bias. Our charity approach (each completed survey donated to a charity that brings video games to kids in hospitals) that we didn't need to promote it as heavily to our own contact. We spread the word successfully through contacting RebelLabs subscribers, VirtualJUG and London Java Community (LJC) members and individuals in the industry. That said, there are certainly some JRebel users in there, although we didn't ask specifically.