"Advertising is like learning:
Too little is a dangerous thing."
- P.T. Barnum
Audiences do not see the first insertion of an ordinary advertisement.
The second insertion they see, but do not read.
The third insertion, they read.
The fourth insertion, they look at the price.
The fifth insertion they speak of it to their spouse.
The sixth insertion they are ready to purchase.
And the seventh insertion, they purchase.
Your object in advertising is to make the public understand what you have got to sell.
And if you have not the pluck to keep advertising until you have imparted that information, all the money you have spent is lost.
So the person who advertises at all, must keep it up until the public knows who and what they are, and what their business is - or else the money invested in advertising is lost.