Surely what they are saying they are doing is not really possible. They cannot with certainty verify who is paying who. They might be able to make probabilistic statements, but not certainty in all cases.
depends on what exactly they offer.
if they are connected to more thn 75% of the network they certainly can tell what region of the world sent this transaction out first (not who crafted it... except if running bitcoind himself)
not sure who are this anonymous financial companies interested in this.
i'd say (tinfoil hat) its a service for nsa/bnd/fsb and so on