The main idea of a loaded word in advertisement is to

It is to influence the reader.

Loaded words is a term used for words that can persuade a consumer to buy or use a product or service based on the way something was advertised.

A commercial (which is a type of propaganda) that uses the technique of loaded words which incorporates words with strong connotation, whether positive or negative, to make the consumer feel a certain way. We simply associate the product with the positive emotion that the loaded words give us.