Facebook, Amazon and Zynga bet on social web

Facebook, Amazon and Zynga will invest in a fund to help entrepreneurs develop applications and services for a new era of the social web.

The lion's share of the sFund's $250m (£160m) will come from venture capital firm Kleiner Perkins Caufield & Byers.

Details were announced at an event at Facebook's California headquarters.

"There's going to be an opportunity over the next five years or so to pick any industry and rethink it in a social way," said Facebook's Mark Zuckerberg.