Many local blood banks are for-profit enterprises. I would never donate there unless the only alternative was not donating. While there’s nothing wrong with selling the collected blood (as do the Red Cross and the non-profit blood banks), if the goal is to make a profit instead of covering expenses then choices are going to be made as to which hospitals to serve and what prices to charge based on something other than the most effective way of meeting needs. Furthermore, I’m the guy who does all thw work to manufacture the product – why should my desire to help others let somebody else get rich with no benefit to me?
I almost exclusively donate to the Red Cross now – I find their operation much more sophisticated and (aside from occasional long waits) I have confidence that they are neither going to slice me up nor waste what I give them.