Not sure about the rest of the EU, but at least in Germany, plasma donations at private collection companies are a common way for students to earn beer money or end-of-month money, as you can donate plasma every couple days.

You also get paid for "normal" blood donations, even though the payment is technically only a "compensation" for your time and trouble. The donation services like German Red Cross usually still make a profit, which is why some people make a point to donate directly to hospitals if possible.

In the EU I imagine your plasma donation will go to someone under your socialized medicine system who needs it at no or low cost to them. In the US it will be sold at a very high cost by a series of for profit firms.

Organ donation works the same way. It can be very profitable for the hospital and others involved. However we ban the sharing of those rewards with the people who actually provided the organ in that case.