Every year, just before the annual holiday season gets underway, senior management and HR leaders of companies across sectors convene meetings behind closed doors where they discuss two of the most critical topics on their agenda: Performance and compensation.

For many of these firms, these meetings are the culmination of a weeks-long or even months-long process of compiling data and gathering feedback. The aim of most of these meetings is to be as fact-based and objective as possible. But, as anyone who has sat in on such a meeting or whose evaluation is determined by the people who join such a meeting knows, the human element plays an important if not always transparent role in the evaluation process. 

It's what Carla Harris, Vice Chairman and Managing Director at Morgan Stanley, discovered in 1988 when she joined her first "roundtable" meeting at the firm, the evaluative meeting where they discussed the performance of the analysts, associates, vice presidents, and managing directors. In a recent Ted Talk, Harris describes the "aha moment" she had while sitting in on the meeting, and the lesson she learned from it.

Here's what she discovered:

"I cannot tell you how important it is to have a sponsor. It is the critical relationship in your career. A mentor, frankly, is a nice to have, but you can survive a long time in your career without a mentor, but you are not going to ascend in any organization without a sponsor. It is so critical that you should ask yourself regularly, 'Who's carrying my paper into the room?' And if you can't answer who is carrying your paper into the room, then I will tell you to divert some of your hardworking energies into investing in a sponsor relationship, because it will be critical to your success."

So what is a sponsor? Here's how Harris defines it:

This person that is carrying your interest, or as I like to say, carrying your paper into the room, this person who is spending their valuable political and social capital on you, this person who is going to pound the table on your behalf, this is a sponsor. This is a sponsor.

Why do you need a sponsor?

You need a sponsor, frankly, because as you can see, there's not one evaluative process that I can think of, whether it's in academia, health care, financial services, not one that does not have a human element...There is a measure of subjectivity in what they say and how they interpret any objective data that you might have. There is a measure of subjectivity in how they say what they're going to say to influence the outcome. So therefore, you need to make sure that that person who is speaking, that sponsor, has your best interests at heart and has the power to get it, whatever it is for you, to get it done behind closed doors."

How do you find a sponsor? Harris says you need to cultivate two types of currency at work: 

...Performance currency is the currency that is generated by your delivering that which was asked of you and a little bit extra. Every time you deliver upon an assignment above people's expectations, you generate performance currency...Performance currency is valuable for three reasons. Number one, it will get you noticed. It will create a reputation for you. Number two, it will also get you paid and promoted very early on in your career and very early on in any environment. And number three, it may attract a sponsor. Why? Because strong performance currency raises your level of visibility in the environment...

Relationship currency is the currency that is generated by the investments that you make in the people in your environment, the investments that you make in the people in your environment...It is important that you invest the time to connect, to engage and to get to know the people that are in your environment, and more importantly to give them the opportunity to know you. Because once they know you, there's a higher probability that when you approach them to ask them to be your sponsor, they will in fact answer in the affirmative.

What's her definition of a sponsor?

If you're looking for a sponsor, they need to have three primary characteristics. Number one, they need to have a seat at the decision-making table, they need to have exposure to your work in order to have credibility behind closed doors, and they need to have some juice, or let me say it differently, they'd better have some power. It's really important that they have those three things.

How do you enlist the support of a sponsor? Here's Harris's advice:

And then once you have identified the person, how do you ask for one? The script goes like this. 'Jim, I'm really interested in getting promoted this year. I've had an amazing year and I cannot show this organization anything else to prove my worthiness or my readiness for this promotion, but I am aware that somebody has to be behind closed doors arguing on my behalf and pounding the table. You know me, you know my work and you are aware of the client feedback, and I hope that you will feel comfortable arguing on my behalf.' If Jim knows you and you have any kind of a relationship, there's a very high probability that he will answer yes,and if he says yes, he will endeavor to get it done for you.