Marketing, Advertising and Propaganda: What's the difference?

What is the difference, in your opinion between marketing, advertising, and propaganda?

Marketing, advertising and propaganda are three types of media that never seem to sleep.  They are always there for us when we are in need of a new product or service, but how can someone tell the difference between the three?  Although very similar, these three types of media each have significant differences from one another.  

To me,it seems that marketing is the first step a company takes before they begin advertising and propaganda.  In order to be able to advertise, companies need customers that are interested in their products.  In order to find loyal customers, companies must develop a marketing strategy to gain and maintain relationships with customers.  Once a company has done that, I feel like advertising plays the next key role.  Advertising seems to be the way companies convey their products to customers through different mediums; whether it is television, radio, magazines or billboards.  When advertising, companies must find a way to effectively bring the service or product to customers attention.  As for propaganda, I see it as a form of advertising in a persuasive manner instead of just stating facts and information about the product or service.  It also seems that propaganda could be more about one company bringing down another company that produces a similar product in order to better their own product.  

Do you feel that propaganda is a way of advertising? why or why not?