Online influences use online sources for their info

From Digital Edge and Rob Runette:
A recent study of Washingtonpost.com readers who are deemed to be Online “influentials” — a group said to represent the 10 percent of the population that shapes the attitudes and
behaviors of the other 90 percent — say that the Internet is their top
form of weekday media, according to a new poll conducted by RoperASW and
washingtonpost.com.
According to the study, this group relies heavily on the Internet, with 86 percent using it to research places to visit and 82 percent using it to research what to buy. Most also say
that they actively pass along the information they receive to friends and
acquaintances.
One question that interests me is how we can quantify the value of a referrer network–I get the value of the friends of friends referrers of friendster, ryze, etc. but how about referrals of information and news–what is their value and how do we measure that?