Once, I was hired for a writing job by walking into the editors office and throwing a folder on his desk.
Another time, I was promoted to outside salesman by having business cards made and cold calling on commercial construction companies. When I brought my first set of blueprints in for a quote, the owner said, "I didn't know you were my salesman," to which I replied "I must've forgot to tell you."
Recently, I arranged a retail distributorship between a maker of popcorn and a substantial grocery chain in the midwest. While representing my practice at a special needs convention, I met a young man with Down Syndrome and Autism who had started a flavored popcorn business. So motivated was I by his story, that I was inspired to help him grow his business. So I went to the corporate headquarters of the grocer, got myself in front of the CEO, and pitched him on the benefits of doing business with my new associate. And he picked up what I was putting down.
But what's really exciting, is that I haven't even got started yet. I am in the process of getting licensed as a financial advisor with an international financial juggernaut offering an array of services so vast I can barely comprehend it. Finally, a company big enough to fulfill my destiny. I will manifest a career so profoundly awesome that I will be a legend of my industry; competitors will shrink at the mention of my name, women will swoon as they drive by my billboards, I will be the greatest advisor in my company, I will use part of my wealth to capitalize new businesses in my community.
I have foreseen it, and I realize it a little bit, a day at a time.
Anyway...
To answer your question, you must show them AMBITION. Are you a desk-riding and clock-punching, as my grandmother sais, "bump on a log"?
Or are you a bold, imaginative, ingenuitive, take the bull by the horns badass with an insane desire to succeed, like me?
Show them AMBITION.
Show them INITIATIVE.
Show them YOU MAKE IT HAPPEN.
In your mind should not be "I need more money". In your mind should be "how can I be of more service, how can I be invaluable to my employer?"
Also, WaterTiger's more technical post is highly apt. She sounds like a hot cougar, I want to have sex with her.