RSS of course, except for one thing: there is no viral aspect to RSS. If you belong to my feed, no one else knows. Your friends don't know. At least with twitte

RSS of course, except for one thing: there is no viral aspect to RSS. If you belong to my feed, no one else knows. Your friends don't know. At least with twitter, once you follow me, people who like you may check out who you follow (assuming it's not in the thousands :-) Other people here quoted a ratio of 10 to 1. That sounds about right. How the viral aspect (and growth) of twitter changes that number when you look at tour subscriber growth over a year, I don't know.