In Australia, they call thongs what the rest of the world call flipflops. In Australia, such footwear like these thongs are an important part of the laid back lifestyle, so for those that need to wear foot orthotics, they either do not wear them or they can not wear thongs or flip flops. That is where these Archies Arch Support Thongs come in. They were developed in Australia by a physiotherapist to provide some sort of arch support on a thong or flip flop.
They have about 2.2cm of arch support built into them which is very similar to what most premade orthotics have in them, so they are a sensible viable alternative or adjunct to foot orthotic therapy.
The Archies Arch Support Thongs are selling very well in Australia and are highly recommended there by Podiatrists. A lot of podiatry clinics sell them and a lot of them use them for themselves and their families. For more on the Archies, see these links.