Ethics of Subliminal Messaging: Carnegie Mellon's Gates Center

I'm curious to know, what are your views on the ethics of using subliminal messaging on students?

The reason I ask is that I'm currently a CS student at Carnegie Mellon University. As many of you may know, the Gates Center was built due to generous funding from Bill Gates. However, as I walked through the halls of the new building for the hundredth time, I realized something quite intriguing.

In certain areas of the building YOU CAN HEAR VOICES! No these are not ghosts. After some investigation, I found extremely small hidden speakers designed to project sound towards one location. However, they spoke so softly that the average person would not realize that there was even any noise.

However, at closer inspection, these speakers appear to say three phrases repeatedly (at least that I could make out): "Microsoft Server", "Dell", "Computer Science."

Seeing as how Bill Gates himself funded the building, and Dell provided the computers inside the building, this hardly seems like a coincidence that subliminal marketing is occurring within the Gates building itself.

Now I pose the question: does anyone else find a problem with the fact that students at Carnegie Mellon are subconsciously being enticed to buy from sponsors of their university?