You need to decide what type of person you are. Most successful people know their value, and won't accept less. They'll be on to the next position at another company before they take less than what they are worth. I made it a point to show to my boss how much more in billings I was bringing in than the rest of his team. If you create value, you have a right to ask for some of that value. Just do it respectfully.
Employers are supposed to be paying attention to who is doing the work. Sometimes, you have to make it apparent to them, if they are obtuse. Most of the time, when it comes to billings, it falls under the 80/20 rule. 20% of your employees are bringing in 80% of the work. Not everyone hustles, and a smart manager realizes that not everyone is created equally. You have to pay the 20% better, because if you don't, they leave, and the company loses billings.