It's not really a secret. All plasma exits the country to get processed and expired/unused is given away or sold.
What Happens to YOUR Donation:
Canadian Blood Services wants to ensure that as
much of every donation as possible is used while
continually improving the cost-effectiveness and
efficiency of the blood system. Giving or selling unused
or end of shelf-life parts of the donation instead of
discarding them could contribute towards this goal.
Proceeds of any sales would be invested back into the
blood system to balance out costs.
https://blood.ca/sites/default/files...rochure_EN.pdf