(Or maybe "chick bait"?) Researchers in Britain claim men are more likely to give to charity when an attractive woman is face of campaign-- and another man has donated first.
"British researchers examined evidence from various online fundraising sites and found that men often donate more money to a campaign run by an attractive woman—if another man has already made a large donation to the same project. The behavior is probably subconscious, say the researchers, but it does provide evidence of something called 'competitive altruism.' Some psychologists have previously observed that people tend to act more generously if they believe they are being watched by others, for example." -- Robert Ferris, CNBC.com