Many examples exist of the following phenomenon: a bicategory B (distributive and with further structure), an additive category A, and a "cardinality functor" # : B -> A. The cardinality of a finite set, the dimension of a vector space, the cardinality of a species, all fit into this pattern. I discussed the following important example. Let B be the bicategory whose objects are finite groups, arrows from G to H are finite dimensional left G, right H modules. Let A be the additive category with objects same as B, but arrows from G to H are class functions G H -> C. Then the character of a representation provides a cardinality functor. (Which preserves biclosed structure, global tensor product, etc.) The fact that it preserves composition is a fundamental fact not usually stressed in standard books on group representation.