While these are the most comfortable flats I have ever worn, I'm giving them a one star review. I purchased these about a month ago and have worn them 4-5 days a week since to work. I work in a carpeted office, mostly at a desk, and wear them outside only when walking in and out of the building. I have not ran a marathon in these shoes. Despite this, there is already a large hole (probably the size of a nickle) in the sole of the shoe - you can see straight through to the carpet. Given the price and reliability of this brand, I am extremely disappointed in these shoes, which is very sad considering how many other pairs I wanted to buy. I've had $10 Target flats last longer than a month.