How does getting a Fortune 500 client contribute to your business?

A lot of startups and entrepreneurs make incredible efforts to acquire the holy grail of customer logos - the Fortune 500's. We just launched our own product here: https://www.producthunt.com/post... (take a look if you're curious). I wanted to understand what does such a client actually do to a business...increase the market confidence, act as an anchor for others to know you're trustworthy, is it chasing big money or something else completely. Appreciate your thoughts!