Just as important as a hard run is the recovery afterwards so you have recuperated in time for your next hard run. A number of runners are now using recovery sandals or flip flops to give their feet a rest after that long hard run. This type of footwear is typically soft and arch supporting so the foot is well supported and rested. With shoes like this, the tired muscles do not need to work so hard, so recovery is facilitated. An important part of increasing fitness and preventing a running injury is that the body is full recovered before the next hard workout takes place. Runners and all athletes are looking for any edge to help that recovery as they now know that the recovery can be just as important as the training. This type of recovery footwear is just one of the many strategies used to help recovery.
As these types of footwear typically have some sort of arch support built into them, they can be very useful in those who have foot orthotics as they will continue to support the foot. Some even use them as an alternative to foot orthotics. The arch support that is built into this footwear will be good for the average foot as that is what they are made for. They are not going to be too good for that if your foot is too far away from being average. In addition to the arch support these shoes are typically very well cushioned.
There are several popular brand on the market. There is the Oofos brand common in the USA and the Archies brand in Australia. In Australia they call flip flops, thongs, so you have to be careful with the terminology that you use. You only have to check out some of the common running websites and the well-known running magazines to see just how many advertisements there are for this type of footwear to realize that how much importance that runners put on these.