Answer:
It is the electronic version of junk mail or a salty meat in a can.
They can float and tickle, but their sound is rarely heard unless you're a pillow or bird. What are they?
What is often returned but is never borrowed?
According to the music industry, you can count on a midnight train and the devil to turn up here.
A mighty weapon in the war against winged household pests.
I appear in the morning. But am always there. You can never see me. Though I am everywhere. By night I am gone, though I sometimes never was. Nothing can defeat me. But I am easily gone.