I hired Marco for his first job (at Vivisimo which I co-founded). He didn't do particularly well (I don't think being a regular employee fits him) but he did work on some things that he ended up leveraging later on at Tumblr and for Instapaper. He actually left because his girlfriend wanted to move to NY. He had a low GPA in college and we hired him because he did a lot of things outside college (like writing his own games) and that impressed us.

I would have never guessed that he would do so well after leaving and that let's me wonder how many Marcos there are out there doing average jobs in average companies. Out of 200 employees that we hired before being acquired by IBM more than a dozen went on to create their own companies - none yet as successful as Marco's.