Even if they were completely selfish, Radiohead makes any money lost by their DRM free stance back on press and popularity. Based on what I've read about them, this isn't how they operate at all, but it's nice when you can change the world and make a profit at the same time.
While I agree that Radiohead makes money from all the publicity of their DRM free stance, I don't really think they are losing money by giving it away.
Radiohead's net profit has been estimated to be between $6 and $8 a cd downloaded. Most bands only make around $2 an album. Digital downloads earn an artist even less. And usually major labels are in charge of an album's production, but take the cost out of the artist's gross. Basically artists can sometimes pay more of the costs of cd production than the label does. So I doubt Radiohead would have made more money from downloads if they had used a label.
And as you mentioned, there are the benefits from the press and popularity. Also, Radiohead has a database of their fans who were willing to download the album. That has to be valuable to them to.
