Google created a ranking system based on reputation. They have a ranking formula called PageRank :

PR(A) = (1 − d) + d(PR(T1) / C(T1) + … + PR(Tn) / C(Tn)

Where PR(A) is the PageRank of page A;
PR(Ti) is the PageRank of the Ti pages that link to A;
C(Ti) is tehe number of outgoing links of the page Ti; d is a variable factor that is between 0 and 1. (Source: Wikipedia)

With this formula and your query Google calculates in what position you are listed in the SERPs. The PageRank is a very wise algorithm and that is one of the main reasons that make Google the most consulted Search engine globally. This ranking can be also tricked, as many people knows, but this is something I ‘ll leave for another entry.

There are different reputation systems in internet. To give another interesting example the reputation on Wikipedia it’s beggining to be measured depending on how much time the changes that the users made to a document last. It’s intuitive right ?
If your change is not solid then someone will come over and change it again.

Another very different thing is the when the ranking is based on popularity as in digg. What we were discussing is about the concept of reputation, something that can be extended and be applied to many other things.
Reputation is a social phenomenon and thus can be used to measure trust for user feedback and Karma. That’s what the forums, digg and other sites are already aware off.

In next entry I will post something about tricking page Rank and how some people is obscuring the Search Engine Results page to bring more people to their sites. This is something that Google may penalize removing your site from their index for some time.