Can you explain how the cost of trying another service is high? If you hear about another search engine that's supposed to be better, it seems easy enough to try it for a few searches or compare results. Seems like plenty of people tried Duck Duck Go and others, but they simply weren't better.
The other way to beat google at search is to disrupt/obviate the search market the way that the social networks are purportedly trying to do. Which I'm entirely skeptical about.
The cost is the feeling you get when you bring up a Bing search that doesn't have what you're looking for and thinking that Google probably had exactly what you wanted. It's the unknown factor: what am I missing by not using Google?
To overcome this psychological disadvantage a search engine has to do a significantly better job. Here's how they could succeed: if you search for "Italian restaurant" and the first result becomes your favorite restaurant. Then your search for "indie music" introduces you to a new site that you visit daily. If you can provide the user with 3 or 4 of those types of wow experiences it can have the effect of changing the psychology of "yeah, but what does Google return?".
Here's the wrong approach: Blekko. Blekko's basically saying "we give up, we can't interpret your query so we're going to ask you to do the heavy lifting for us. We'll index and rank your opinions". You're not going to convert people by making it harder to do searches.
The other way to beat google at search is to disrupt/obviate the search market the way that the social networks are purportedly trying to do. Which I'm entirely skeptical about.