It should have been obvious, but I needed Diego Doval to point out that people don’t always agree on what the relationship means. Combine with Loïc Le Meur’s equally obvious observation that it is too rude to say no. And you realize that managing unsymmetric relationships is going to be a problem.
Your potential benefit from a relationship depends upon your partner’s perception of the relationship. If you must place a public value upon a relationship, then you’re apt to lie to create the perception of a equal relationship. And choices made using that value will be wrong.
Complicating matters, the value is hard to conceal. Some information is revealed every time the value is used determine a decision path. Generate enough decision paths and the value will become apparent. If you’re so inclined, then you could generate paths for the express purpose of determining the value.
It is going to be interesting to see what the Social Networks will do. I can not see them resisting the use of relationship strength since three degrees of strong are more effective than two degrees of weak. But since they can not both use and conceal that strength, they will need to make unsymmetric relationships acceptable.