It's not the size of the reward that matters -- it's who it's given too. If you want results, divide the millions between everyone who lives within one block of where he dies. Then tell everyone how much money they would win. Yeah, win.
The psychological impact will be a passive support of Americans. Then later, self justifications -- they're not traitors to the cause, they really like Americans.
Have American PR firms do lotto type ads -- asking Iraqi women how they would spend their share of the reward. "How would your family spend $3,000?"
Trust me, for many that's more than a years pay, and they'll help. Walkin' around money -- dreams of cold cash, and dead terrorist. As a perk, because no family would receive a huge sum, they would convince themselves they wanted al-Zarqawi caught.
Good idea. That's why we currently offer a $25 million dollar reward for him: