Jon Udell:

"How do you count subscribers in the RSS network? [...] Radio encodes the name/password credentials for these special feeds. As I understand it, this is effectively a group credential shared by all RU users. There's a relationship between UserLand and the Times, not between individual RU users and the Times. But it's easy to see how, using standard e-commerce techniques, the Times could arrange to invidualize its relationships with RSS subscribers."

For a personal blog it makes sense to provide free unregistered access to full posts in RSS format, but we're certainly going to stop doing that for our more commercial ventures.