If you've been recently promoted or accepted a new position, chances are you didn't ask for enough money.

According to new research by Jobvite, the leading analytics-driven recruiting platform, "only 29 percent of job seekers negotiated their salary at their current or most recent job," leaving money on the table.

To put this into better perspective, we're talking 71 percent of the workforce blew their chances of increasing their earning because they weren't comfortable having that awkward conversation to ask for a pay raise.

While the prospect of negotiating may equal getting a root canal for those who hate it, if the conditions and approach are right, it's still the best and simplest route to increasing your income.

Yet for job seekers at their current or most recent position (2,287 workers total were surveyed, 1,531 in the U.S.) the Jobvite report found that:

  • Only 29 percent of job seekers negotiated their salary.
  • 48 percent still don't feel comfortable negotiating at all.
  • Only 56 percent of men overall feel comfortable negotiating, versus only 38 percent of women.
  • At their current or most recent job, 26 percent of women negotiated vs. 32 percent of men.

Then, there's that whole gender pay gap thing...

It's widely known that men still earn more than women for similar jobs, as evidenced by the latest Simple Truth about the Gender Pay Gap report. Some attribute the idea of a "confidence gap" being the cause for women asking for less money.

Freelance journalist and writer Emma Cueto has a different take. She writes in Bustle that the real reason women don't negotiate pay isn't a lack of confidence, but rather the response they tend to get when they try. She cites strong empirical evidence in multiple studies that suggest four reasons why women don't negotiate pay as often as men:

  1. Employers penalize prospective female employees for negotiating. Trying to negotiate, writes Cueto, "is probably going to get you nothing but ill-will as a woman."
  2. Employers also don't like their own female employees asking for a raise. It's a lose-lose.
  3. Male employers don't like women to negotiate pay, while not minding it when men do the same.
  4. Cueto writes, "Studies have shown that even though people don't like women to ask for more money for ourselves, it's OK if we want to advocate for other people."

Negotiating works, whatever your gender.

The Jobvite report stated that, overall, 84 percent of those confident enough to ask for more pay were successful in getting it. 80 percent of women, in fact, say their negotiation resulted in higher pay, while 87 percent of men surveyed reported the same. In addition, about a fifth of those who negotiated were rewarded with a significant pay increase somewhere between 11 to 20 percent.

Think about it: If you're making $60,000 per year, and you're in the 48 percent of job seekers who are too apprehensive to negotiate, you're potentially leaving $12,000 of extra income on the table for that home or vehicle purchase you can't afford now.

But don't blow your raise on material possessions. Ramit Sethi, author of New York Times bestseller, I Will Teach You To Be Rich, says "a one-time salary increase of $5,000--properly invested--adds up to over $1,300,000 by the time you retire."

5 Negotiation Tips from an Expert

Sethi offers five negotiation techniques that, he says, will score your own $5,000 raise.

1. The briefcase technique.

When you actually prove you deserve that raise, and explain how your work translates into more profit or savings for the company, "you'll instantly grab your boss' attention," writes Sethi. "You literally open your briefcase and give a document to your boss with a clear and compelling rationale for why you deserve a raise." It should show that:

2. Use comparables to justify a higher salary.

"The ideal is to have multiple real offers on the table that offer a higher salary. The next best option is to find comparable salary ranges for your industry, location, and business type using Payscale.com, Salary.com and Glassdoor.com", states Sethi.

3. Prepare your boss to give you a raise in six months.

Rather than waiting and praying, says Sethi, "you need to let your boss know that you want a raise and pre-agree on what criteria you need to hit in order for that to happen." Sethi says setting the right tone is key. "You need to connect with your boss emotionally and make sure the tenor is nice and relaxed. The last thing you want is a defensiveness." Then, adds Sethi, agree on a mutual target goal that is ultra-specific. Once you agree on a number, get it in writing. Finally, circle back in six months and say, " You said it would take X to get a raise. I've done X and more. I'd like to have a discussion with you about that raise."

4. Know exactly how you'll respond if your boss objects.

Sethi says display your gratitude for the unappealing offer and reiterate your excitement for the opportunity to make the conversation "collaborative rather than adversarial." Then, put the emphasis back on the value you will bring to the business, not the cost of your salary increase.

5. Know what salary you want.

Have a specific number and be prepared to justify why you're worth what you're worth before a salary negotiation. Otherwise, says Sethi, you'll be at the mercy of a more experienced hiring manager who will control the conversation. He says, "When you know what you want, not only can you communicate that crisply to the other person, you can demonstrate why -- and this forces you to prepare for the negotiation. This single distinction can be worth thousands to you."