And assuming 10 equal payments at the end of each of the 10 years, each percentage point of average return Craigslist sees on that $1 million they earn 55,000. In addition to a getting to presumably write off some portion(all?) of the $100,000 they would be donating each year for tax purposes.

So really they get more than $2.1M value out of this.

Edit: Yes, I realize there is no reason I should assume 10 equal payments over 10 years, given the information available. It was just the closest thing to an 'average case' I could define for a situation like this.