While many of us attach far less importance to CPM when evaluating redemptions now than just a few years ago, if a friend of mine was on the verge of redeeming AA for 1 cpm, I'd step in and try to find something better. If I couldn't, I'd offer to front them cash. AA miles, in particular, are still quite useful. UA miles are also okay, as long as you are fine with economy class award tickets (this took a while to get used to, but I'm okay with it now). DL miles are definitely the worst of the three, but there are some remaining sweet spots, and it's usually possible to get at least 1.2 cpm on domestic redemptions.