Although cute and comfortable out of the box, I quickly realized these were torture devices disguised as flats. I didn't get blisters at all but I had very red and very deep indentations in my heels because the flat stays in its curled position. The curled position puts pressure on the back of my heel and even after a generous break in period there was no relief. Sadly my quest for an inexpensive flat has ended with this experience and I bit the bullet buying a more expensive flat to avoid the pain.