Depending on the shoe I wear a 6B or 6.5B. Due to the length of the top part of this shoe, I could only get my foot in half way in which I'd expect if this shoe were a size 4. The overall quality for this price point was okay, but I'd be very disappointed if I'd paid the listed price. I also bought a pair of their pumps which are also a size 6B and they fit tight on the sides and are a little loose on the heel but at least I can fit my feet in them. I'm debating if I should return them as well since plain low heel leather pumps are hard to find.
Addendum: Amazon views it my fault that these shoes run small thus I am required to pay for return shipping. I just thought you should be aware of this return policy.