"There are many values to a mile - yours, mine and the bloke down the block's."

Right on. MY miles are worth exactly what I get for them, NOT how I earned them. If they are absolutely free and I get nothing for them they are worth nothing. If I pay $1 million for them and get nothing for them they are worth nothing. If I pay $1 for them and get a free trip to Bangkok they are worth quite a lot.
Dave