Motivating a Non-Academically-Inclined Teenager

I've been spending a lot of time thinking about what I want to accomplish this year. One of the things I want to do is find a way to motivate Butterfly to get better grades in school.

Butterfly has a marvelous gift of easily making friends. She is a caring, kind person that attracts boys (I'm really not very comfortable with this aspect of her gift...) and girls into friendships fairly easily. The negative side of this gift is that Butterfly would much rather talk with her friends via phone or chat messaging than do her homework. She'd much rather spend time hanging out and laughing with friends than come home early enough to get her homework done. And she'd much rather think about school social drama than do complete work on any given assignment.

We go through the same routine every quarter: Butterfly starts off getting A's in all her classes, then she'll skip a few assignments and her grades rapidly begin dropping to C's and worse. I lecture her, she gets grounded, we're both grouchy, she gets sullen and rude, she frantically begins trying to catch up and ends up doing less than stellar work, I yell at her, she cries and tells me I don't understand ... you get the picture - it's ugly.

Paying her for good grades hasn't been much of an incentive. I think that 3 months has been too long for her to wait to receive a reward for good grades.

For those of you that think good grades should be their own reward, you obviously haven't worked with a non-academically inclined child. For this child, good grades are just something that makes the parent happy; for MY child, grades are simply immaterial.

I'm tired of yelling about grades. It doesn't make Butterfly WANT to get better grades, it makes us both feel terrible, and it simply isn't working for either of us.

However, since friends are a big deal for Butterfly, and she has said that her friends have treated her to fast food when they've been out together, here's the new plan: I've purchased a few gift cards from the local fast food joints and she can choose one of them when her grades are posted on edline with nothing lower than A's and B's. That should take two weeks or so. She and a friend have decorated a poster with the gift cards attached and have tacked it to the wall in front of the bathroom door. Butterfly will see the cards every time she leaves the bathroom. I'm hoping that two weeks will be a short enough time period for her to keep doing homework before the reward kicks in. As she earns them I'll use cards from different fast food restaurants to replace them. Please let this work!

I've also purchased a purse that Butterfly picked out from the website JustFab.com as another incentive. This  purse will also hang on the wall for her to see and caress while she continues to get her homework done on time. We will wait until progress reports come out before rewarding the purse for grades of only A's and B's. Butterfly asked what would happen if she DIDN'T get only A's and B's on her progress report. I said that the purse would continue to hang on the wall for her to work toward.

I'm running out of ideas. How do you get a teenager to WANT to learn? How do you get that teenager to WANT to do well in school?  How do you get that same teenager to CARE about her education?

Do YOU have any ideas that worked for you?