Reputation systems will solve overhead costs, issues of quality and can be a dynamic representation of individuals, groups, and ideas.

• save time
• save effort
• extend reach
• extend capabilities

Why?
Not everyone can know everything all the time - time, scale,
diversity, overhead, cost, technology, quality, validity, trust

Prisoner's dilemmas - reputation

Tragedy of the commons - only 1% of users actively edit Wikipedia,
lots of freeloaders Passive vs. Active

Homophily vs. heterophily - Diversity vs. Specialized

Many vs. Few - Scalability issues

Diversity vs. Specialized - Not everyone can know everything all the time.

Evolution vs. Fixed - Fixed goes stagnant. Vast power and technology creates ability for rep systems to morph accordingly.

Emerged vs. created - Gatekeepers, moderators, evaluators, experts, users - Passive vs. Active

These are new sites that are trying to build/design reputation sytems:

opinity.com :: to gather all of your "sites" together plus reputation
"score", other people vouch for you

claimid.com :: to gather all of "your" sites together

ikarma.com :: sites that use rating and/or call out bad business sense.

jyte.com :: to make claims

sxip.com :: for business

en.wikipedia.org/wiki/Higgins_trust_framework :: open source framework that enables users and other systems to integrate identity, profile, and relationship information across multiple heterogeneous systems

wink.com :: targets social networking users

linkedin.com :: trying to be a social network and have reputation

digg.com :: lots of gaming the system. ppl with good reps are being manipulated with money to use their influence

consumerist.com :: blog that complains or prasies about various
businesses' policies and ethics

slashdot.org :: news rating system, which heavily relies on the reputations of it's users