“By year 2036, there will be at least 1 man alive in the U.S. who has fathered 150 children.”

The Internet, and online dating in particular, will bring a great deal of transparancy and scale to humans' ability to find a mate. Today we pick our spouses from a small pool of candidates. Tomorrow, the Internet will put millions of candidates right at our fingertips, and we'll know a ton of information about each.

This kind of scale and transparency will make it much clearer who the best men are. There will be far less risk is picking the right mate. Therefore the "best" men will be picked by the "best" women quickly.

The woman in the middle or below in this ranking will face the following choice. Either they pick a mediocre man and get his help raising kids, or get the best man, but not get any of his help raising the kids. Both examples are found in nature.

There will be a cutoff point after which the women will opt for the latter strategy, in a way, voluntarily joining a man's harem. They will approach men and ask them to give/sell them their sperm. The men will happily do so, especially if there is a financial benefit, and no requirement to help raise the child.

As a result, whoever the society deems to be the "best" man will effectively have hundreds of children.

For a more detailed discussion visit:
http://baris.typepad.com/venture_capitalist/2006/03/the_big_web_20_.html