There are millions of reward seats redeemed every year and when dealing with a professional mileage broker (i.e. L4L @
www.flyl4l.com who are the biggest out there) there is really NO risk.
And this is because it literally takes a magician behind the check-in counter to say that this particular seat was purchased through a broker.
Let alone the fact that airlines - despite all their efforts - never managed to make the selling of miles illegal simply because a person who rightfully earns miles (through flying or CC) should be able to use them however they see fit. This includes gifting them, redeeming them for friends AND selling them!
Imagine buying a camera in Best Buy and being told that you can only take pictures of yourself and for yourself??!!!
Or that you cant sell the camera...
I've been using L4L for several years now and they are as good as it gets!