Experts in Spreading the Word

Since I went to school for a traditional English and Literature degree, I left school knowing about the must-reads of British and American literature from eighteenth century to the present. Interning in advertising and a small newspaper, I quickly assessed and confirmed where my interests lie. Curious to learn more and understand the connect between brands and consumers, my current experience in public relations is definitely adding to my knowledge of "how things work." However, I can't seem to settle, what the difference is between marketing and PR? I can't help but think these two roles might be double dipping. Think about it - let's say you're creating a campaign to raise awareness for something. Where does marketing come in, wouldn't you tap into a PR company? In the PR world, marketing is used as a verb (let's market this by doing XYZ), but marketing folks like to think they are the "big" idea... Being the biased PR girl that I am, I would like to say, PR is queen and marketing follows the lead. In the interest of expanding knowledge and spread the word, like any good PR girl, here's what I know about PR and marketing.
PR is about measurement and reputation - how many people know about you or your product or your message and how many people like it. PR has control over messaging and trends. Here's an example, Kleenex is a household name, my guess is some savvy, super cool PR girl working for Kimberly Clark refused to call it tissue until it caught on. She probably called people, stalked the internet and called it monitoring, and threw an event called "Dry your eyes here's a Kleenex" - a relationship forum for women going through break ups/divorces/PMS. So there you go - message spread, PR = A+*. So, then what is marketing? If marketing is the management process that establishes how to execute successfully to satisfy both consumer and organization... is the difference how the brand relates to you vs how you relate to the brand? Courtesy of Ads of the World, here's the best answer I've received.

Interesting right? Choose your field wisely, where do you want to fit in, when it comes to brands, the message and the recipient.

*Fictional analysis, not actual