Value of Organic search engine optimization

What's the value of organic search engine optimization? It apparently contributed quite a bit to the $410 million that the New York Times paid for About.com.

Much discussion here about how search engine optimization has helped about.com. Much discussion about how SEO has helped About in driving traffic in this Online Journalism Review article, About.com CEO explains why NYT spent $410 million to buy site.

Organic search engine rankings are very valuable and are like the gifts that keep on giving. It takes a lot of time and dedication to achieve good organic listings but usually you keep them and that results in a steady flow of traffic going to your site.