FlySAS.co.uk has launched an affiliate scheme on Tradedoubler
Amongst other Nordic routes, SAS fly to Copenhagen, Oslo, Stockholm and not just from Heathrow. They also fly from Gatwick, London City, Birmingham, Manchester and Aberdeen. In addition to their own flights, passengers can book codeshare flights through the SAS website, for example to Helsinki with Blue1.
Worth a look if you have some relevant sites / traffic. The Northern Lights are all the rage at the moment so also worth some attention is the Iceland Express affiliate scheme.