According to a Forrester Research study, only 6% of Americans read blogs and only 2% use RSS. The report recommends to leverage early adopters (i.e. bloggers and blog readers) for viral activities. Find influencers and use them to spread the word. Sounds very much like PR.
Another item mentioned on Forrester's summary page I picked up was that "Households with a laptop and home network watch three fewer hours of TV per week and read the paper an hour less per week than offline households do."