It looks to me like Joann's is experimenting with their discounts for various groups of people. The 10% VIP (guild/group/charity) discount is always available, as is the 15% discount for teachers. Lately they have on occasionally offered a senior discount and a military discount. They have also bumped the teacher discount up to 20% once or twice. And then they offer percent off discounts to all customers once in awhile. It means you have to be watching their ads all of the time in order to find the narrow special discount windows. And always read the fine print!
Dayle