A lack of access to Cuba,says GAO, has made it difficult to obtain nationally representative data on audience size, and decision-makers have had limited information to assess the relative success or return on investment for each transmission method.
VOA: standard.2009.06.18
Alternative B would require two independent networks foreach verification method, PIN and signature, for a total of four networks to each card.
Or to put it another way, the way the Merlin data are compiled is a bit like allowing football clubs to each have a different methodfor deciding how many league points they get from matches.