Shake Shack is having its Annual Great American Shake Sale and asking customers to #ShakeItForward. No, there's no dancing involved, but this deal might make you feel like busting a move. When you visit a Shake Shack now through May 13 and donate at least $2 to No Kid Hungry, you'll receive a voucher for a free milkshake on your next visit. It's that easy—make a donation and sip on a free chocolate, vanilla, caramel, cookie, or whatever flavor you're feeling shake. 

No Kid Hungry is a campaign run by the non-profit Share Our Strength, which works to end hunger and poverty in the US. Shake Shack started their Annual Great American Shake Sale to support No Kid Hungry back in 2012 and since then, the burger chain has raised over $2.5 million for the campaign, and according to Shake Shack, has helped kids get 775 million healthy meals.

You can find a participating Shake Shack location near you, and when you're picking up your ShackBurger or trying out the new BBQ Cheddar & Bacon menu, don't forget to donate. A free milkshake is awesome, but helping end child hunger is even better.