A small case study, very small case study, posted at DigitalPoint Forums shows how a person who has Google AdSense on three different sites, has the highest click through rate on his ads on the site that is most tailored to women and girls.
(1) Woman tailored site has 40% CTR with 200 uniques a day. (2) Cell phone site has 1% CTR with 500-600 uniques a day. (3) Unknown site has 2% CTR with 1200 unique visitors a day.
He concludes that women are more likely to click on contextual ads.
Well, that is a hard conclusion to make. Of course, the target user is a huge factor in one's earnings. But there are a ton of variables on any single page that can encourage and influence a person (male or female) to click or not to click.
Forum discussion at DigitalPoint Forums.