Think back to CW circa 1997. The internet is too complex to find the most relevant results by machine. These things must be hand-indexed. There is no better way to do it.
All Google does is guess as to what the "most relevant" results are. What you and your friends say/do/click/whatever is just another data point in the model. Presumably, it trains itself based on the results you/others actually click.
Google will almost certainly model how much a particular friend influences a particular search. It almost certainly will help, and certainly can't hurt (in the long run, if the weight goes to zero).
All Google does is guess as to what the "most relevant" results are. What you and your friends say/do/click/whatever is just another data point in the model. Presumably, it trains itself based on the results you/others actually click.
Google will almost certainly model how much a particular friend influences a particular search. It almost certainly will help, and certainly can't hurt (in the long run, if the weight goes to zero).