I shall now feel very altruistic - or not.
I suppose they want to motivate people to donate blood regularly, but personally I'm quite happy with the bag of biscuits, chocolate and juice they give out to every donator. And since I give blood in two different cities, this wasn't my tenth donation anyway. I think today I'm at 17.
So, nice idea, if a bit unnecessary, but the text on the certificate couldn't be much more corny.