This was trending yesterday:

http://searchengineland.com/googles-eric-schmidts-berlin-speech-biggest-search-competitor-amazon-205761I've had similar thoughts myself over the last few years, as my wife and I use Amazon almost exclusively for all internet purchases. I haven't clicked on a paid search ad in years, mostly because I don't see them as much; I'm not making the commercial queries that are more likely to trigger paid ads in Google - I'm making them in Amazon. Evidently I'm not the only one....

What do you folks thing? Do "walled-garden" ecoystems like Amazon and Facebook inevitably represent more of a threat to Google's revenue than Bing or any other traditional search competitor?