In chapter 4, Hilliard discusses the three kinds of announcements found in broadcast and Essay

In chapter 4, Hilliard discusses the three kinds of announcements found in broadcast and cable television and in radio:

Commercials, which sell a product or service for money

PSAs,  which do not sell a product or service for money but is
made on behalf of a non-profit organization or activity and can include
advancing an idea or policy

Promos, which promote the station, channel or network itself

All three are perhaps the oldest forms of strategic communication
in video.  All three also found in the world of the internet; between
game plays on apps, before streaming videos, on social media pages.  In
your opinion, what differences exist between commercials, PSAs and
promos on the air and online?   Whether or not there are, should there
be?  If so, what?  Explain your reasoning.