CO offers the "extra mile" to gold elites for only $75 - with NO mileage cap.

So in my case, $75 gets me (if my travels next year match the previous 10 years on average) at least 25,000 bonus miles - or no more than $.003 per mile (most likely less than that)... for me this is a no brainer (at least 25,000 for $75)

However, I personally would NEVER pay more than $.01/mile - so for some people, the $100 for maximum of 10,000 is not such a great deal if you're not certain that you'll achieve 20,000 status miles.

cpd