Originally Posted by MissMiles

I'm not sure about intra-european flights but there is great value in biz or first FROM europe TO the US. You may have to be flexible with dates and sometimes seats open up a few weeks before, sometimes they open way in advance. I agree that paying 30k miles + $200 in taxes for an economy ticket isn't the greatest of redemptions if the flight costs $600 (or whatever) because that's only a $0.013/CPM. However, paying 52.5k miles + $300 in taxes for a business class ticket that costs $5,000 is a great value ($0.09/CPM).

CPM is cost per mile, so you take the net cost of the flight (after taxes on the award) and divide by the number of miles. The higher the CPM the better, which happens on biz and first class flights bc of their cost.