Many shopping mamas toss a dollar in the bucket or on their bill at the checkstand, wondering how retailers determine which charity to support.

Target is taking a different approach with Bullseye Gives, which asks Facebook users to go online and vote how the company should distribute the $3 million it donates to charities on a weekly basis. Visitors can choose from 10 leading charities and see, in real time, how much money the institution will receive that week. Currently, St. Jude's Children's Research Hospital has a commanding lead, with one quarter of all votes.