Knit classes - BOGO

I was in my local Michael's yesterday (3/16/12) and saw a sign advertising all bed, knitting, and fine arts classes at buy one get one free. When I asked how long this would be offered, the clreks said they had no ending date. No one officially told us (the teachers about this and this is a corporate decision. The manager was unavailable at the time to ask how this affects our pay. Has anyone heard how long this campaign will be?