From my understanding we have an overabundance of promo codes out there and some of you get paid from them.
Here are the reasons why you have been dropped to 2.5% on a 10% off promo code. It's really simple after a month that its hasn't been used it will drop for your cut, so if you had been making 10% and a month went buy and it wasn't used you will automatically drop to 2.5%.
If your promo code isn't working, you went more than 2 months without a purchase being made. From this point it will automatically be removed.