Wine list pricing

In a forum I sometimes read, there was a long thread about pricing of wine list at resturants. I agree that many places are getting out of hand with there per bottle pricing. But in Cleveland (yes, I know it's not the center of the wine world) we have many places that have 1/2 price bottle on a specific night, buy a bottle $40 or higher and you get a gift certificate, 5 diamond resturant with a wine list that won't break the budget, wine bottles are only marked up by $10-20 from retail cost. Most places who are trying these various methods are selling more wine and getting more customers to come back, so why aren't more doing that?