In a Mega Sale situation, you MUST purchase 5 participating items (in this case) to get the additional mega savings of $1 per item. So, for example you have a cart full of groceries, but you count only 4 items. A filler item is what you grab to get your item count up to a multiple of 5 so that you can get the mega discount on all of your items. Preferably something very inexpensive that doesn’t require a coupon, because if you had a coupon – it’s probably already in your cart!
Don’t forget you can view the Mega Event full inclusions list HERE.