For some people, receiving feedback isn't that important. In that case, there's an additional option you can choose: "180 seconds, no feedback." This option means that the recipient must listen for at least 180 seconds (3 minutes) before giving a decision, but does not have to write any feedback if they do not enjoy the song. You'll see this option when you are creating your campaign.
You can read more about the "180 seconds no feedback" option here.