Firefox Bug Bounty Program will be paying more for reported security bugs. Also, the program will be moving to a variable pay-out based on the quality of the bug report, the severity of the bug, and how clearly the vulnerability can be exploited.
The Mozilla Client Security Bug Bounty Program is designed to encourage security research in Mozilla software and to reward those who help to create the safest Internet software in existence.
Read more here - https://blog.mozilla.org/security/2015/06/09/upcoming-changes-to-the-firefox-bug-bounty-program/