For one, they pass on fuel surcharges on their partner award flights and I'm not sure how much those fees can be. (uponarriving.com)
It's recommended to stick with short haul flights as they pass on fuel surcharges for award travel, greatly increasing the cost of long flights. (johnnyjet.com)
The availability of points flights can vary from airline to airline, while the rules and fees associated with fuel surcharges also differ between carriers and destinations. (moneysense.ca)