The S-1 speaks for itself.
Back in mid-late 2009 Andrew Mason asked me to be on the Groupon board of directors. He wanted my opinions and advice on product development, design, copywriting, software development, and user experience. Andrew (and Brad and Eric) know where I stand on building bootstrapped, profitable businesses. I still stand there. I wasn't asked to be on the board to give them financial advice.
I agreed to be on the board. I like Andrew a lot and I was very happy to help him. I had never been on a board before so I saw it as a great learning experience for me as well.
Groupon compensated me for my involvement with options.
A few months ago when Groupon took a big round, I was asked if I would like to sell some of my shares. I said yes. That sale is listed in the S-1. I still have more shares. I don't see any problem morally or ethically with selling shares that I was granted as part of my involvement with the board. I owned something, someone offered to buy it, and I sold it.
I was asked to leave the board of directors in January of 2011. I serve as an advisor now. Whenever Andrew asks me for product, design, or writing advice, I'm happy to help.
I've never invested my own money in Groupon or any other private company. It's not that I wouldn't invest in a private company, it's that I haven't.
Those are the simple facts.
As for my credibility, I don't see how any of this is relevant. You can make up your own mind about that. I believe today what I've always believed - net profits rule, bootstrapping is the way to start a business, and spending less than you earn is the only way to have a healthy relationship with money.
As for DHH's opinions, they are his own. I may or may not share them, but we're both grown ups and we respect each other no matter what.