I generally agree with mmmgirl rather than thespy.
Chances thread can be inaccurate, but with enough responses, a consensus can begin to form. Given the variety of people here, there will be opinions not only from "high school seniors" but people who have stayed on much longer, like me, who have gone through the entire application process and even went through four years of college.
All the colleges value a lot the rigot of the high school cirriculum. GPA is not very meaningful without the list of courses taken and the selectivity of the high school.
You want something from your audience, and that includes their time. If you want a good return, offering to chance them back is usually helpful as well
