jefmcg
Guru
Different focus in different countries. Australia seems more widely interest in different uses, so even if you don't produce sufficient platelets, they have still many other uses for the plasma.
Edit: Wrong again. In fact plasma donation and platelet donation are 2 separate things. I'll stop being "helpful". Though I am now guessing platelet separation takes longer, as I am pretty sure it took nothing like 3 hours for me, and I am a very slow whole blood donor.
But I think I may have found why they are particularly interested in your negative blood.
http://www.donateblood.com.au/about-blood/anti-D
Other thing I learnt from google: US as well as Australia only take donations once a month (though I remember it was safe to give more often). Maybe that's because the commitment turns away so many donors, that they end up with less by taking it every fortnight, as seems to be indicated by comments in this thread.
Edit: Wrong again. In fact plasma donation and platelet donation are 2 separate things. I'll stop being "helpful". Though I am now guessing platelet separation takes longer, as I am pretty sure it took nothing like 3 hours for me, and I am a very slow whole blood donor.
But I think I may have found why they are particularly interested in your negative blood.
http://www.donateblood.com.au/about-blood/anti-D
Other thing I learnt from google: US as well as Australia only take donations once a month (though I remember it was safe to give more often). Maybe that's because the commitment turns away so many donors, that they end up with less by taking it every fortnight, as seems to be indicated by comments in this thread.