Have you ever had one of those days when all you could think was, "Gosh, do I need a vacation."

Of course you have -- because all work and no play isn't good for anyone. A vacation doesn't have to be two weeks on a tropical island, or even a long weekend at the beach. A vacation just means taking a break from your everyday activities. A change of pace. It doesn't matter where.

Everyone needs a vacation to rejuvenate mentally and physically. But did you also know that you can help boost our economy by taking some days off? Call it your personal stimulus package.

An analysis by Oxford Economics for the U.S. Travel Association found that more than 40 percent of U.S. workers don't take their full allotment of paid time off (PTO) during the year, representing an average of 3.2 unused vacation days per worker in 2013 -- a total of 429 million workdays!

Aside from the risk of exhaustion and career burnout, unused vacation days have a negative impact on the U.S. economy as a whole. The study estimated that if employees took full advantage of their PTO days, the economy would enjoy the benefits of more than $160 billion in sales and $21 billion in tax revenues, as well as supporting 21 million jobs in areas like retail, transportation and manufacturing. Workers taking just a single additional day off would boost spending by $73 billion.

So go ahead and take some vacation. It's your patriotic duty.

And please, don't try the old excuse that you can't take time off because your esteemed presence is required at all times. No one is indispensable. No one. The place may not function as smoothly without you, but chances are the doors won't close, and you won't lose all your customers.

My friend, the late Zig Ziglar, had an interesting take on productivity and vacations: "Isn't it amazing how much stuff we get done the day before vacation?" So let that be your motivation: getting lots of work done in anticipation of being out of the office.

Summer is traditionally a great time for a vacation. Have you planned some time off yet?

You can detach from the workplace without worry and enjoy the break you deserve if you follow these simple steps before you leave:

-- Notify co-workers and clients. Let bosses, customers and colleagues know you'll be on vacation at least a week -- if not sooner -- before you take off. Let people know how long you'll be out of the office, when you'll be returning and who they should contact in the meantime. Set an auto-reply on your email, and leave the same information on your voice mail.

-- Prepare your co-workers. Talk to the people who will handle questions or problems while you're away. Help them troubleshoot by providing pertinent information like the status of current projects, names of possible callers and reasons they might call.

-- Straighten up. There's nothing as unmotivating as coming back from a great vacation to a workspace in complete disarray. Make the transition easier by cleaning up before you leave.

-- Get your mind in gear. If you are not accustomed to taking time off, you may have forgotten how to disconnect. It typically takes two to three days to get into vacation mode. A friend usually downloads a photo of his destination for his screensaver a couple weeks before vacation. It reminds him to enjoy the rewards for his hard work.

-- Turn off your electronics and explain that you will be available for no more than 15 minutes a day unless the place is on fire. Our smartphone world has created an army of work zombies. The temptation to work is too great when you can just tap your phone. Don't let technology ruin your break ... or your life.

-- Trust the people you work with to carry on. You might be pleasantly surprised at what gets accomplished in your absence.

And if getting away from the office is absolutely impossible, try what the Business School of Happiness calls "The One Minute Vacation." When time and money prevent taking a physical vacation, "The same relaxing benefits of taking a vacation can be found in minutes of simple meditation interspersed throughout the day. In fact, three one-minute sessions of deep breathing taken at pre-set intervals throughout the day may indeed deliver the deep sense of peacefulness that might have seemed elusive."

Mackay's Moral: Vacations aren't luxuries, they're necessities.

Once the famous Chicago merchant Marshall Field was walking through his Chicago store and heard one of his clerks arguing with a customer.

"What are you doing?" he asked the clerk.

"I'm settling a customer complaint," said the clerk.

"No, you're not," said Field. "Give the customer what she wants."

Is the customer always right? If you are a business owner, the answer almost always is yes. Otherwise, they aren't customers. They are people who do business with someone else.

Years ago, I saw a study for Travelers Insurance that showed persuading people to complain could be, in fact, the best business move a company could make. Only 9 percent of the noncomplainers with a gripe involving $100 or more would buy from the company again. On the other hand, when people did complain and their problems were resolved quickly, an impressive 82 percent would buy again.

I have a philosophy about customers -- ours or anyone else's. A customer who has a good experience with a company will tell five other people. But a customer who has a bad experience will tell 15 other people, and with social media today, it can become tens of thousands. So anything I can do to decrease the bad while increasing the good is right at the top of my agenda.

Part of that philosophy assumes that you will get a second chance. If you get that chance, don't mess it up. You may be looking at the best customer you've ever imagined.

Customers can also be your best teachers. True, you often learn a lesson the hard way. But it's an education in Customer Service 101 that you won't learn in any school.

Stew Leonard, founder of a famous chain of supermarkets in Connecticut and New York, said: "Customers who complain are your friends because they are giving you a chance to improve instead of just walking away."

No one likes to hear that they have done a lousy job, but criticism from customers is more valuable than praise. You want your customers to tell you when you screwed up, so that you can take care of the problem and take steps to ensure that it doesn't happen again -- to them or anyone else. If they don't tell you, they will walk away and they'll never come back. Worse, you are likely to alienate someone else in the future by doing exactly the same thing.

To paraphrase a famous line, ask not what your customer can do for you, ask what you can do for your customer.

Now put the shoe on the other foot. Think like a customer. Stop to consider whether your own customers are receiving fair treatment. When you have a complaint, you want it addressed quickly and fairly. When you approach the problem from the customer's side, the view is quite different.

As consumers ourselves, we should be able to expect a satisfactory result. When you don't get what you paid for, agree to, contract for, or reasonably should expect, you should look for a resolution to the problem. And you should give the vendor the opportunity to fix it. Isn't that what you would want your customers to do? Remember, most reputable companies want to make the customer happy.

I recommend following these steps:

-- Determine the solution you want. Do you want a replacement, your money back or some other remedy? Be specific so you can convey from the start that you expect a resolution to the problem.

-- Start in the right place. Don't go to the CEO of the company until you've exhausted the lower rungs. Customer service is usually the best place to start. If customer service can't help you, ask to speak with a manager.

-- Target where to take your complaint next. Don't just call headquarters and voice your complaint to the receptionist. Find out who has the authority to address your complaint.

-- Control your emotions. When you're overwhelmed with frustration, vent your anger in a letter -- but wait a few days to decide whether to send or rewrite it. Humorous complaint letters are more likely to get noticed and acted upon. Also, remember to single out those employees who tried to help. Praise can be just as effective as criticism.

-- Keep copies of all correspondence. A good record of your attempts to resolve the problem can be helpful if you ultimately need to take legal action.

Mackay's Moral: If a business knows what's good for it, it knows what's good for a customer.

In 1935, Charles Darrow brought a board game to Parker Brothers. The experts at Parker Brothers rejected the game, Monopoly, for "containing 52 fundamental errors."

The persistent Charles Darrow had spent the year after his rejection demonstrating the potential success of the game by selling numerous editions of the board game himself. Ironically, in 1936, Darrow was well-received by the embarrassed Parker Brothers, which eventually helped make the unemployed heating engineer from Germantown, Pennsylvania, a multi-millionaire.

Since that time, over 275 million copies of Monopoly have been sold in 111 countries. Each year Parker Brothers prints more than $40 billion worth of Monopoly money -- more than twice the amount printed annually by the U.S. Mint. Monopoly's success has produced 6 billion of those little green houses, enough to circle the globe.

Charles Darrow was hardly the first or last person who showed persistence and had a strong belief in his product. Many famous Americans have packed up their product and sold it out of the trunk of their car.

Phil Knight, founder of Nike, sold his first shoes from the trunk of his green Plymouth Valiant. Curt Carlson, founder of Carlson, the world's largest hospitality company, Radisson Hotels and TGI Fridays restaurants, sold his first Gold Bond trading stamps out of his car.

Wayne Dyer wrote his first book, "Your Erroneous Zones," in 1976. He told me that when his publisher didn't want to promote the book, he felt so strongly that he decided to sell it himself. Dyer purchased the remaining copies and drove from New York to California, stopping at bookstores along the way and sleeping in the car. He also did as much media as he could. One night while doing a 2 a.m. radio interview, one of the listeners was Johnny Carson. He booked Dyer on "The Tonight Show," and the rest is history. Dyer has since sold more than 35 million copies of "Your Erroneous Zones" and written over 30 other books.

Few people had as difficult a time getting their invention accepted as Alexander Graham Bell. Even U.S. President Rutherford Hayes said of the telephone in 1876, "... who would ever want to use them?"

Chester Carlson, another young inventor, took his idea to 20 big corporations in the 1940s. After seven years of rejections, he was able to persuade Haloid, a small Rochester, New York, company, to purchase the rights to his electrostatic paper-copying process. Haloid has since become Xerox Corp.

In the 1950s, Bette Nesmith Graham began using white, water-based tempera paint and a thin paintbrush to cover her typing errors. She sold her first bottle, originally called Mistake Out, in 1956. Graham later patented the office product. After starting out with just 100 bottles a month in sales, Liquid Paper was selling 25 million bottles a year when Graham sold it for a reported $47.5 million in 1979.

In 1927, the head instructor of the John Murray Anderson Drama School instructed student Lucille Ball to "Try any other profession. Any other." I wonder what would have made him say "I Love Lucy"?

Buddy Holly was fired from the Decca record label in 1956 by Paul Cohen, who was known as Nashville's "artists and repertoire man." Cohen called Holly "the biggest no-talent I ever worked with."

Chuck Yeager, the famous test pilot, threw up all over the back seat on his first flight as a passenger. He vowed never to go back up again, but eventually he reconsidered. Then he became the first man to break the sound barrier.

These are all examples of ordinary people with extraordinary persistence. None of these folks was famous or rich or even particularly successful before their big breaks.

We've all heard it before, but there really is no substitute for persistence. In fact, persistence is sometimes as important as talent. It must come from within. You either want it or you don't. Giving up is not an option.

I remember when I was first starting out and asking a colleague I respected how many sales calls he would make on a prospect before giving up. He told me, "It depends on which one of us dies first."

Confucius said, "It does not matter how slowly you go so long as you do not stop."

Don't be discouraged. It's often the last key in the bunch that opens the lock.

Mackay's Moral: A flower has to push through a lot of dirt before it can blossom.