The effect is the same -- like I said, they're selling more FC seats for less $. CO has long been relatively indifferent between a B fare and a Z fare for its elites -- by offering elites what is, in effect, a modest discount on first class fares (and a way around corporate travel policies), they are attracting more business and selling more seats. And that business traveler who is elite on CO, and may or may not be elite on a competing airline on that route, could very likely steer the ticket purchase to CO if s/he was getting the free upgrade, even if the CO flight was somewhat less convenient than the competition. More FC seats, for less $, but still pretty good yields.