It struck me as I looked through the responses from our Best Places to Work submissions that Metric Theory, the company that took top honors this year, did not list any special perks on its employer survey.

Among the things its employees valued most were the relationships they had with their co-workers, the work they did and the vision shared by their leaders. In an age where there is so much discussion about amenities, it is refreshing to see that what people value most doesn't cost a dime.

People have joked that there are CEOs out there asking their leaders to "Get me one of those cultures!" In fact, when it comes to the subject of culture, likely the most important thing to remember is that it cannot be bought or "gotten." Culture is created by the leadership and the values of the organization, not just through words, but, more important, through actions.

Charles Day, CEO of the Lookinglass, puts it this way: "Culture is a consequence of values. It is an output, not an input. As a company grows, it must constantly assess and reassess its values to ensure they are relevant to the business they want to become -- and vice versa."

In fact, Metric Theory's CEO, Ken Baker, underscored this point when he explained that the digital agency's values have evolved as it has evolved, but the threads have remained consistent. Within the first two days of an employee joining the company, Ken or his agency co-founder, Adam, meet with them and share a core set of principles that guide how employees approach one another and the work they do, which are reiterated at the company's quarterly all-hands meetings.

Metric Theory's principles: To be solution-oriented, bring a positive attitude to the workplace and help other team members without expectation of something in return, because everyone will find success in the collective. Here are some things to keep in mind about core values:

• They are not marketing-speak. And they should not be developed by the head of human resources, either. They should be created by the leadership of the organization and revisited as leadership changes and the company evolves. Shafqat Islam, CEO of NewsCred, wrote out the company's core values and shared them as a Google Doc with the whole organization, allowing every staffer to suggest what should be added or deleted.
• They shouldn't be locked up in the company manual. Companies as long-standing as Johnson and as new as HomePolish make company values part of their onboarding process and post them on their walls. LinkedIn and our winner, Metric Theory, constantly refer to them in their ongoing all hands meetings. And in some cases, they're tied to compensation, as is true with Indian aerospace manufacturer Aequs.
• They should be emphatic. John Adams, chairman of the Martin Agency, recently shared with me the core values that have been working for the agency for more than 25 years. They are utter integrity, deep mutual respect, striking creativity, genuine joy, amazing accomplishment and unending self-improvement. He said that the adjectives are just as important as the nouns, because they are extreme versions of these words. John said that the best way the values live on in the organization is through stories shared as part of the company's history.

I'm not trying to say that some perks are unappreciated. Warby Parker co-founder Neil Blumenthal mentioned during his recent Advertising Week New York panel that messing with office snacks can be a huge distraction. The company learned that when it tried to adjust its snack options—it turns out people do love their peanut M&M's. But our Best Places to Work winner shows that perks alone aren't the most important way to create a positive workplace. If you're looking to improve your culture, start with values, not M&M's.