Perusing the Jerusalem last night, unwittingly in my Wikipedia sweatshit, I was asked about my donation this year. On the tail of my positive response I richoceted the question. "Yes," he responded "you had the picture of the cute girl [on the banner]."
Internal measurements of banner ad effectiveness are well examined in the Wikimedia foundation. If it's found that pictures of attractive young female editors sell donations faster, should that be exploited. Or is sexism for a good cause, still sexism?