We study the algebra of BPS Wilson loops in 3d gauge theories with N=2
supersymmetry and Chern-Simons terms. We argue that new relations appear on the
quantum level, and that in many cases this makes the algebra
finite-dimensional. We use our results to propose the mapping of Wilson loops
under Seiberg-like dualities and verify that the proposed map agrees with the
exact results for expectation values of circular Wilson loops. In some cases we
also relate the algebra of Wilson loops to the equivariant quantum K-ring of
certain quasi projective varieties. This generalizes the connection between the
Verlinde algebra and the quantum cohomology of the Grassmannian found by
Witten