Baobab indicates that Diners Club standard is 1 Club Rewards point for every dollar charged, and then 2 points per airline mile. Since I've signed up, they've called me a "premier" member, and it's been 2 points per dollar charged, so that the ultimate dollars/miles ratio is 1/1, the same as airline-linked credit cards. I didn't do anything to be premier, they just set me up that way. Maybe it's different for overseas members, but in the US a 2/1 dollars/miles ratio would be a competitive disaster.