Gone are those days, when you had to spend humongous amounts on monotonous still write ups to be published in the newspapers. Every advertisement can be available to thousands in just one click.
In the past times, thousands who read your advertisements were maybe not the right customers to approach.
A 60 year old female reading the advertisement of an IT course. In this case, advertisements did knock on the door of the market, but not on the doors of the right people.