Subliminal advertising?

When I was on my way to a dinner event yesterday, I found myself crammed into an MRT caboose that was filled with blood bank advertisements. They were using various "Fact style" statements such as: "Do you know that blah blah blah". What amused me was the red colored thought bubbles pasted strategically on the windows such that it seems that they originate from the people sitting right beneath them. It says: "I think you should donate" (something like that, I can't remember the exact wording).

What is interesting is the usage of *you* in the message. It made it look like the person sitting there is asking whomever he/she is looking at to donate blood. I felt that the message might have been more effective if it said: "I think *I* shall donate" instead, as it gives a voluntary feel, instead of the current 'you are being arrowed' feel.

Which brought me to my next thought. Who's paying for this advertisement? In some parts of the world, people can get payment from selling body fluids, but I am pretty sure that blood donors here do not get anything (maybe a drink and a cookie). The money has to come from somewhere.