Without being able to properly research the three groups of marketing, advertising and propaganda it difficult to create a conclusion on how they differ from one another. The normal reaction to this would simply be that the three coincide with one another constantly. In my opinion, advertising and propaganda take two separate directions away from marketing but must always begin with marketing.
Marketing is the backbone to both advertising and propaganda. Marketing consists of tons of research to figure out which market sector your group, organization, etc. would advertise or use propaganda towards. Through marketing, some of the steps that the organization would have to figure out is the market in which they want to impact, the message they want to get across and their budget.
Once an organization can complete their marketing techniques, then they can move forward to the form of advertising or propaganda they wish to create. In my eyes, advertising is creating a message towards a consumer group that tells the consumers what they should or should not do. For example, Apple may say in their advertisements, "Our MacBook Air is the lightest laptop ever." This tells the consumer that if they are looking for a light laptop then they should most certainly consider purchasing the MacBook Air laptop.
Propaganda on the other hand is not always directed at a specific consumer group. Also, it can have multiple meanings. While, advertising is created to get across one specific message. Propaganda can be in the form of art work, such as a graffiti, or even just a poster. Although the creator of the piece of propaganda usually wants to get across some sort of a point, it is up to viewers of the piece to decide what to make of it and let it effect them in the way they choose.
With this being said, what seems to be a more convincing piece of marketing? Propaganda or advertising?