Offering money works: http://www.google.com/about/appsecurity/chrome-rewards/
Vulnerabilities != Exploits. Chrome may have the most, but they may be minor.
Bad analogy. Where there's frayed cord, either it can be fixed before there's worse consequences (as in bugs discovered in targeted attacks or reported for a cash bounty) or after (bugs generally exploited in the wild).because where there's smoke, there's never fire.