A means for the illiterate to acquire political opinions. Talk radio operates on the philosophy that a person should choose a side in political debates (usually either 'staunchly liberal' or 'staunchly conservative'), then incorporate that side into their personal identity. This frees them of the need to submit to bothersome processes like thinking for themselves.
Talk show enthusiasts can be identified by their dogmatism and easily excited sense of self-righteoous indignation.
Paul the burger flipper learned everything he knows from talk radio.
A means for the thinking people of the country to discuss such matters as politics and social issues. Most popular talk radio is of a conservative nature, which is due to the strangle hold that The Left has on main stream news organizations.
You will know people who regularly listen to talk radio. They are usually employed, have a sense of right and wrong and follow a code of ethics.
Paul the burger flipper listened to talk radio while paying his own way through college. Now he owns his own company is doing just fine.