From their own FAQ:

Does Kite provide 100% protection against mosquito bites? Kite provides a steady stream of our patent-pending spatial (airborne) compounds that block mosquitoes’ ability to track us for up to 48 hours, but it does not guarantee mosquitoes will not bite us. It is being designed to be a replacement for spray-on, fan-powered, or lotion applications, but does not take the place of bed nets at night and/or appropriate clothing in mosquito-impacted areas

So, they have put some compounds, that have been proven to repel mosquitoes in laboratory conditions, on a patch. The "minor" problem is that this patch can't possibly exude enough of those compounds to protect a human in real life conditions. I'm only refraining from calling this a scam because it seems to be a real company with scientists and all. But I won't be spending any money on this patch, that's for sure. http://xkcd.com/1217/