It’s tempting to do something drastic when parting with a company on less than peaceful terms. Bitter employees that quit want to leave their mark on the company and fired employees want to have the last laugh. Andrew Mason, CEO of Groupon was sacked earlier this week, but before he left he sent a company-wide memo that wont soon be forgotten.

After four and a half intense and wonderful years as CEO of Groupon, I’ve decided that I’d like to spend more time with my family. Just kidding – I was fired today. If you’re wondering why… you haven’t been paying attention.

As “spending more time with my family” is corporate code for getting fired or phased out, Mason starts off sounding bitter and spiteful, but his perspective about where he has taken the company and where it needs to go is evident as you keep reading. He seems to know that it will grow with fresh talent in his position.

If there’s one piece of wisdom that this simple pilgrim would like to impart upon you: have the courage to start with the customer. My biggest regrets are the moments that I let a lack of data override my intuition on what’s best for our customers.

The letter was internal, but created with the knowledge that it would go public anyway. This was a good PR move because it saves his reputation. He’s been on the chopping block for months now as his company’s stock and profits plummeted. Handling this gracefully makes him appealing to other companies because they know he’s not a liability. When times get tough he won’t point fingers and slander their name.

But what about leaving a company Goldman Sachs style, with a glowering New York Times op-ed denouncing everything the corporation stands for? Almost a year ago, Greg Smith did just that. The piece discussed how poorly employees treated clients and how little they thought of customers. Critics were split on Smith. Half thought he was right to call out Goldman Sachs for their sleaziness while the rest believed it was career suicide for stabbing the company he gave 12 years to in the back.

I knew it was time to leave when I realized I could no longer look students in the eye and tell them what a great place this was to work…I attend derivatives sales meetings where not one single minute is spent asking questions about how we can help clients. It’s purely about how we can make the most possible money off of them.

His general tone is sadness, not anger. He mourns the loss of integrity and yearns for transparency and better customer relations. He’s attacking the company, but only because he wishes it would improve. The full article is worth a read to understand the effect customer service has on company culture.

Both Smith and Mason’s departures were followed by considerable news coverage. Smith will always be known as the guy who wrote the New York Times article about Goldman Sachs – he even went on to write a book about it. But Mason has a chance to use this memo as a stepping stone in his career. He’ll get scooped up by another corporation and will be known as the CEO of XYZ instead of the guy who made Groupon stocks plummet 77%.

We’re not all CEOs of major corporations and CNN probably won’t run to our doors when we face career changes. As badly as you want to send out that scathing email while you’re packing up your desk, be an Andrew Mason, not a Greg Smith. It’s better to keep bridges intact as you move onto bigger and better things than be that guy or girl who badmouths their previous employer every chance they have.