Returning home from an international business trip I struck up a conversation with the guy seated next to me. Turns out we were both tech industry execs with a lot in common, except he was older, more experienced and apparently wiser.

Toward the end of the flight we somehow got on the topic of relationships. This guy had been married forever and I wasn’t sure my wife and I would get through the year. He gave me a brilliant piece of advice that I’ve never forgotten: Do the unexpected.

It’s funny how the big things – expensive gifts and grand gestures – never seem to make our spouses as happy as we think they will. It’s the little things, the unexpected things, that matter most.

Bringing home her favorite chocolates when it isn’t Valentine’s Day. Giving her a single rose from the garden. Doing the dishes. Saying, “Let’s go out” when you know she’s tired and it’s her night to cook. Saving her a trip into town by picking up groceries on the way home from work.

Do I actually do any of that stuff? Wouldn’t you like to know? All I know is that trip was 15 or 20 years ago and I’m still married. Yes, to the same woman; don’t be a smartass.

In any case, the guy was right, and about more than just personal relationships. As it turns out, doing the unexpected is key to success in business, too. After all, the next big thing is never what anyone expects.

Pretty much everyone passed on Google until one guy, Andy Bechtolsheim, realized that Larry Page and Sergey Brin were onto something and cut them a $100,000 check – an investment that would come to be worth billions. And it wasn’t even the search engine but AdWords, which didn’t launch until late 2000, that made Google a household word.

The media unanimously thought Apple was crazy to get into the hyper-competitive cell phone business. Likewise with opening retail stores. And one pundit called Apple’s iPad “good for nothing” and “just a gigantic iPod Touch.” Look how all that turned out.

When Evan Williams bought out Odeo’s investors for a few million bucks, a side project was discussed but nobody paid much attention, including some very smart and accomplished VCs and investors. That side project was Twitter.

Doing the unexpected benefits businesses in lots of other ways besides product innovation.

When it comes to customer service, tell me what makes you walk away feeling great about a brand: when they finally give in and cut you a break after you spend hours and days complaining to tone deaf service reps, or when they treat you with respect and do the right thing without hesitation right off the bat?

Likewise, the key to motivating employees is never what you’d expect. It’s not a big paycheck that rocks their world but being empowered to do their best work and make a real difference. They want to be recognized and rewarded for their performance. And an unexpected promotion, raise or bonus goes a long way.

Don’t get me wrong. I’m not saying it’s a good idea to randomly pull the plug on projects, back out of commitments at the last minute or change strategy at the drop of a hat. Chronic leadership chaos can wreak havoc on an organization, not to mention the business. I guess the same is true of personal relationships, as well.

If you use a little common sense, doing the unexpected will yield unexpected benefits.

Image credit Michelle Tribe via Flickr

A version of this first appeared on Entrepreneur.com.