I may be wrong (often am) but I think Hemispheres was redesigned a couple of years back by Pentagram in SF and that they set it up to be respectful of illustrators, not that they're doing a trade for promo.
Robert Saunders February 23, 2006
United may or may not be trying to bargain with illustrators by giving them more "exposure", but I've always known Jamie Easler, Hemisphere's AD, to be illustrator-friendly. He is still there, last I looked. Regarding Frazier, he's one gem of a guy when you meet him in person. He's a pro-active, smart marketer of his work and maximizes every opportunity he encounters. Wouldn't surprise me in the least if he thought of the website link himself. But also I think it's not unusual that parties are thinking up this no-cost way of optimizing the illustrator's exposure.
Leo Espinosa March 3, 2006
So I guess a spot illustration flyes you from La Guardia to Newark.