Airports (Part iv)

SylVie left for her second Project Abroad today, this time from the relative luxury of CDG 2F.  She's flying with Korean Air, via Incheon Airport in Seoul, for the simple reason that it was cheapest and yet gave her Air France airmiles.  This despite the fact that the Seoul detour added a few hours and 2000 km to her trip.

How many extra miles are flown and extra barrels of kerosene consumed with such economics?