The four P’s — people, product, price and promotion — are often cited as the keys to a  successful business. Yet this list omits a vital ingredient that has characterized Virgin companies throughout our 40 years: Fun, with a capital F.

When we started Virgin Atlantic in 1984, we had some great people and lots of good ideas about how to do things differently . Sadly, we did not have a lot of money to take it to the streets. Compared to the giant establishment players of the time — TWA, Pan-Am and British Airways — we had a tiny fleet, if one plane qualifies as a fleet, and a miniscule advertising budget.

We could not do much about the single plane — leased from a generous man at Boeing. We had to make the most of our meager marketing money. At the urging of the late Sir Freddie Laker, who made an art form of grabbing the limelight for his airline, I quickly became a willing victim in all kinds of wild and crazy adventures to promote the fledgling Virgin Atlantic. You couldn’t buy a quarter-page ad on the front of The New York Times, but when my sinking boat or crashing balloon just happened to feature the distinctive Virgin logo, there we were.

We also started to run some funny, pretty direct and usually highly topical advertisements to grab the public’s attention.

Such “in your face” ads were largely unknown in the stodgy world of airlines, so our approach quickly gained us notoriety, press coverage and, above all, visibility. The humor stood out against our moribund competitors, and soon Virgin Atlantic itself — not just the ads –became synonymous with a cheeky and upstart personality and, more importantly, a fresh, different approach to commercial aviation.

Marketing teams in London and New York frequently reacted quickly to the day’s news and, within 24 hours, placed tactical-response advertisements in key markets. The day after John Sununu, then White House chief of staff, was castigated for using public money for a limousine to take him on personal trips, Virgin ran a one-off ad saying if only he had booked Virgin Atlantic, he would have gotten the limo for free!

When Gen. Manuel Noriega, the former leader of Panama, was extradited to Miami for trial, we ran a big picture of him, with the caption, “Only one person has flown to Miami cheaper than on Virgin Atlantic!” Sometimes the ads were close to the bone, especially when tweaking the tail of our favorite adversaries, like British Airways. Always, they were irreverent and cheeky. The ads gave the airline a real personality in its early years, which was a key to its success and growth.

Our staff also liked the humor, and the sense of fun. They felt proud to be associated with a company that made people smile and that was seen as a good place to work. We made sure the same spirit ran through everything we did; it was not confined to the cute advertisements. It was crucial that we created an enjoyable atmosphere for crew and passengers alike, at 30,000 feet.

Little touches signified you were on a Virgin flight. Underneath the salt and pepper shakers, modeled on mini-airplanes, we stamped “Pinched from Virgin Atlantic.” The butter knife was engraved with the words “stainless steal.” We put a bar in the upper class cabin so people could chat and socialize – after all, travelling should be fun!

To entertain our passengers, we were the first to put in seat-back televisions. We served ice cream in the middle of the flights. We did everything we could to lighten the mood and the experience. Twenty-five years later, the airline retains that same sense of fun and the ability to surprise and make people smile.

When British Airways sponsored London’s Millennium Wheel in the late 1990s, they planned to make a big splash for the official opening. On the day the wheel was to be raised, the engineers had great trouble lifting it. We jumped at the chance to cause a stir. We scrambled a small airship to drag a banner across London’s skyline emblazoned with “BA can’t get it up.” It was cheeky, all right, and we – not BA – grabbed the headlines that night.

This sense of humor and risk-taking has infused many of our other businesses. Virgin Mobile Canada produced a series of memorable advertisements poking fun at famous people. When Elliot Spitzer, the former governor of New York, resigned over a sex scandal, where he was identified as “client No. 9,” our ads that week showed a picture of Spitzer with a thought bubble proclaiming: “I’m tired of being treated like a number.”

The ads were all about Virgin Mobile’s personalized service. They went on to say: “At Virgin Mobile, you’re more than just a number. When you call us, we’ll treat you like a person, not a client. Whether you’re No. 9 or No. 900, you’ll get hooked up with somebody who’ll finally treat you just how you want to be treated.”

Another ad in the series showed Hillary Clinton with a thought bubble saying, “I wish my bill wasn’t so out of control.”

These ads ran for only short periods of time, but they were picked up in the media and raised the profile of the company and the service.

My books’ titles continue the theme — “Losing My Virginity,” “Screw It, Let’s Do It” and “Business Stripped Bare.” Publishers, however, vetoed “Getting It Up” for my latest book on the history of flight and went for “Reach for the Skies.” We’ll see how it sells!

Over the years I have launched our companies while dressed costumes to amuse our staff, our partners and the press. I have thrown myself off tall buildings, hung off bridges, driven tanks into Times Square and plunged (usually involuntarily) into oceans — all to grab attention and reinforce a sense of fun.

All of it has definitely made an impression and infused that “Virgin feeling” into new ventures. While it is not enough just to be the joker in the pack, if your service and product excel, then making people smile will help you establish a place in their hearts as well as their minds.

Try taking yourself and your business less seriously. You may be surprised that many others will take you more seriously.