As designers we ALL think that obviously our jobs are the most important. And by right, they usually are!
Okay in all seriousness, even as designers I think it's easy for us to overlook the really importance of our graphics and what we design.
There are 7 basic tasks good graphics MUST provide:
1. Reinforce the message---Visually explain the text and content.
2. Direct the reader's eye "Implied Motion"---Nobody ENJOYS looking at a stagnate design. Good use of line, curve and movement creates implied motion and visual interest.
3. Guides the reader---The layout of your design should subconsciously guide the reader from area to area on the piece.
4. Tell a story---What if the reader doesn't have the time to "read" the ad? Can they get the story from the graphics?
5. Good Pictures drive the layout---We've all heard it, "A Picture's Worth A Thousand Words".
6. Maintain Balance---A balanced layout is not the same as a mirrored, symmetrical layout that lacks life. Just the opposite actually, a balanced layout achieves great excitement.
7. Emotional Power---If you walk away from it and it stays with you, then you have an emotionally moving piece. That should be your goal: creating something so profound that you can't get away from it!