Public Relations and New Media

Today, I went to listen to the presentation about "Public Relations and New Media."

What is Public Relations (PR)?
The definition is: A systematic effort to alter public perceptions of or on behalf of a client through the strategic use of existing media outlets.
And what PR do is: inform, persuade, and integrate.

One thing, interested for me was about the PR in Times Square.
The company "Charmin" created public bathroom store there.
Look at this video on Youtube.
Huge public bathroom is in the center of New York City!
This video is public relations. (Is this way of saying correct?)

However, to be honest, I can't distinguish between public relations and advertising.They seems the same for me....

I think I need to review the presentation, but it was interesting moment for me.