Nearly half of interactive marketers use RSS, but consumer adoption has only reached 11%. Of the consumers who haven't adopted RSS, most don't understand how RSS is relevant to their lives and the way they seek information. If marketers expect to reach a critical mass of consumers by using content syndication, then they must take on the burden of education.
I have a news page on a small site and put key headlines on an rss feed. As far as I can make out from the site stats I have one visitor who has used Firefox smart bookmarks and two who have subscribed to the feed with news aggregators compared with a mailing list of around 200.
Basically people seem happy with email and want information dropped into their inbox without having to use any special technology. Of course when they no longer want it they just click the "report as spam" button rather than cancelling.
I am not sure how to get around this as most people really aren't interested in the technology, they just want to read their emails, chat and download music.
The only browser I know that has a feed reader built in is Opera. That's telling as well. You really need a 3rd party app to collect and sort through feeds. Even though I prefer to use another piece of software for this I can see how it would help to have this become more simple for the users.