10 for $10

Why is it that a major food store advertises 10 items for $10. Many people think that in order to get that price, they must buy the 10 items. The food store further advertises that one can mix and match to reach the 10 items. I have passed shoppers with 10 boxes of crackers in their carts, and I have seen shoppers with the mix and match of 10/10 items. This same store also advertises 2/$2.50, regularly 1/$1.50. Again, one must only purchase one of the items to get the sale price. Isn't this dishonest advertising?