Employee perks are a staple of Silicon Valley offices. Cushy transportation, laundry services, and free haircuts are just a small sample of fringe benefits, and startups are constantly trying to one-up each other for the coolest perks. Your office has unlimited organic snack food? I’ll call with an endless supply of M&Ms and raise you an in-house chef.

But workers may not actually care about these perks as much as you might think.

Rate-your-company startup Glassdoor released the results of an employment confidence survey showing that one in five employees rate “office perks” as important. These benefits (such as free food and drink, casual dress, flexible work-from-home policies, and pet-friendly offices) rate ninth in a ranking of the most important benefits. Turns out that medical coverage, holiday/vacation/sick time, and a retirement plan trump snacks when it comes to the workplace.

The study also found that office perks are valued more by employees in the South and Midwest than by people on the West Coast, and that more women than men say office perks are important to them. People with higher salaries also value perks more. Twenty-three percent of employees who earn more than $75,000 a year say office perks are important as compared to 21 percent of people who earn between $50,000 and $75,000, 17 percent of people who earn between $35,000 and $50,000, and 20 percent of people who earn less than $35,000.

The more money people make, the more they seem to care about the extras. It’s like Maslow’s hierarchy of needs for the workplace — when you have a good salary, job stability, and health care, free lunch and gym membership bonuses. People who haven’t seen a doctor for years or are worried about getting laid off care less about bringing their dog to work.

According to Glassdoor, employees this quarter reported greater overall confidence in the job market but increased pessimism about their current employment situation.  More than one in five employees is concerned about being laid off in the next six months, and this concern is most pronounced with employees aged 45-54. Thirty percent of employees are concerned about coworkers being laid off. Less than 50 percent of employees (around 40 percent) believe that their company will perform better in the next six months and/or expect to receive a pay raise.

Forty-four percent of people surveyed reported that their company made changes to the number of staff, organizational structure, compensation, and benefits in the past six months. In organizations that awarded new perks, stock or compensation, initiated large scale hiring, or restored previously cut perks, employees said these changes were positive. In organizations that reduced compensation or benefits, laid off employees, or initiated unpaid leave, employees said these changes were negative. This may seem obvious, but it underscores the point that security and stability, and feeling like your employer has your back, are significant contributors to morale and loyalty. Furthermore, around 70 percent of employees believe their benefits are better than those offered at competing companies. People generally don’t leave their current jobs for better perks at another.

Office perks are widely considered a requirement in Silicon Valley to recruit and retain the best talent. The big guys like Google and Facebook are famous for the cool stuff they shower on their employees, and Yahoo CEO Marissa Mayer’s decision to ban working from home set of a wave of controversy in a world where employes expect (nay, demand) flexibility. “Company culture” is widely discussed as part of hiring strategies, and tech companies pride themselves on taking more progressive approaches to the workplace.

Even small startups feel like they have to offer something beyond compensation, and ultimately a Red Bull refrigerator costs less than a full health plan. However multiple studies have shown that job security and employee well-being are strong drivers of productivity, and productivity is a strong driver of success. You want motivated employees? Give them the things they actually need first, and then break out the M&Ms.

This Glassdoor survey was conducted online with Harris Interactive from June 18 to June 20, surveying 2,084 adults.