Although that's a T&C violation on most airlines it would be hard for them to catch you. Your point about not earning the miles on award tickets is quite valid though. I need all the preferred miles I can get to maintain status, so I buy my tickets and fly the family on miles. I get my PQM's and the cost is greatly reduced. The downside is that I have to occasionally let the wife ride in first while I sit in coach with the kids.