M&M Dance Cru?

OK, I am sooo confused?? How did Miley and Mandy get into this competition? Who is it against? What is the point of it? Was it originally only going to be Miley competing but Mandy got into it too because of the Youtube show? Can someone give me a synopsis of how it started, why it is going on, what is going on, and anything else that would help me understand the M&M Dance Cru competition. Thanks! & obviously it is becoming a big production because the M&M Dance Cru have their own helicopter, shows, and are professionally filmed. Whats the deal?? Thanks!