Work makes up a significant portion of a person’s life, and the interactions that take place there are often powerful and meaningful, even outside of the walls of the company. In many ways it can become part of their identity, and will affect their overall esteem, and happiness. The way that people in an organization interact is a powerful indicator for someone evaluating opportunities at different organizations.
Talking about your corporate culture is a way to humanize your company, letting people know what the overall personality of the organization is, while also giving them an important insight into what it will be like to work there. Often this is more important on a subconscious decision making level than salary and benefits.
The added benefit is that if you can accurately describe, and extol the benefits of your corporate culture, you will be more likely to attract candidates that better fit those values, and whom will be able to contribute to the overall purpose of your organization in more meaningful ways.
Bad: Graphic designer needed for a tech startup.
Good: Tech startup that cares about inclusion and diversity is seeking a graphic designer.