Why is advertising and public relations considered to be the most important components of a marketing communication mix?

The answer to this question depends on who you ask. If you ask a public relations professional, they will tell you that PR is the most important. If you ask a marketing professional, they'll tell you it's advertising. The answer always lies somewhere in the middle. Both public relations and advertising are tools in a marketing toolkit. To determine which tools to use, you need to ask yourself a few questions:

What are your business goals? - Are you trying to sell more products? Or are you trying to mobilise a community to change their behaviour?

Who are you trying to reach? - Who do you need to buy your product? Whose behavior are you trying to change?

What are you trying to say? - What is the message that will resonate with your audience?

Which mediums are your audience participating in/paying attention to? - Are you speaking to people over 65? Maybe Twitter isn't the answer....

Once you've figured out who you're talking to and what you want to say, you can choose from a number of tactics in your "toolkit." The best campaigns use a mix of marketing communications tactics - from social media to media relations to advertising.

The MOST important components of the marketing communications mix are those that reach your audiences in the most cost-effective, and impactful way.