Zipcar CEO Scott Griffith offers a couple of words of advice amid today's Facebook IPO fanfare.

Zipcar CEO Scott Griffith

FORTUNE -- Bust out the streamers and party hats, everybody, it's Facebook IPO Day! The excitement aside, many of us are wondering what it all means.

How, for example, will Facebook actually grow enough to merit its massive valuation? Will the company be able to make money off of mobile? Will it figure out how to sell the massive amounts of user market data it has collected without starting a privacy war? And will this change what happens when I "like" my cousin's sepia-toned picture of mozzarella sticks?

It's easy for us, and probably Mark Zuckerberg, to get caught up in the IPO whirlwind. No one knows that better than Scott Griffith, the CEO of Zipcar (ZIP) who took his company public on April 11, 2011 for $18.00 per-share, a higher price than analysts expected. The IPO, Griffith says, "was probably the best branding event we've ever had."

Brand recognition isn't part of Facebook's (FB) problem. The tech company went public today at a starting share price of $38 per-share, which means the company is being valued at about $104 billion and could raise more than $18.4 billion in proceeds.

MORE: Zuckerberg through the years

Still, in addition to the cash influx and media hype, going public calls for management tweaks. About a year after Zipcar's IPO, Griffith has been thinking about what he learned after Zipcar's transition from a private to public company, and he has some words of wisdom for others in the same position.

Welcome to the jungle

Right when you hit the market, you have to have a stronger sense of who you are than ever, Griffith says, and you have to learn how to express it to other people. "I do think you have to learn the art of the sound byte." You may know who you are, but, he says, "It's important to simplify the company's story down to a very few key messages that you say over and over and over again." More