This is a persuasive technique in which speaker mentions an important event or person to lend importance or credibility to his argument.

This persuasive technique is called appeal to authority.

Appeal to authority is a persuasive technique where the speaker relies on the credibility of another person or event to suport their own argument. It is often considered a fallacy because the speaker depends on the "authority"instead of presenting their own evidence.

Example:

"A commercial claims that 3 out of 4 dentists would choose this particular brand of toothpaste for their own families to use."

In this statement, the dentists are the authority the argument depends on.