Search doesn't benefit from a network effect, whereas social games do. It's the same defense that Ebay/Craigslist enjoy (though admittedly less ironclad). Some

Search doesn't benefit from a network effect, whereas social games do. It's the same defense that Ebay/Craigslist enjoy (though admittedly less ironclad). Someone like Zynga has brutally low customer acquisition costs compared to a new social game developer (because they can cross promote to existing players for only the opportunity cost of showing other low-CPM banners).