People do add notes to advertise I don't know why though I can't imagine it gets much attention.
It's really cheap as you can send it almost for free.
Yup! I mean, we're talking about those things this very minute, so it actually got attention! During the 1Enjoy 1Sochi spams back in January the new tab on /r/bitcoin was full of people asking what those transactions meant. It's effective, indeed!