[snarf]

True, one of the X projects like Glass would be a better direct comparison in terms of resources and headcount. Google Scholar was just the first thing that popped into my mind when thinking of a Google product that is a social charity. Which, of course, is not the right way to think about Maps since the location data they collect is probably some of the most valuable data for their ad targeting.

[gmueckl]

Let me try to describe Scholar from a different angle: Google relies on a lot of experts in their respective fields in order to be successful. And they need to stay close to the state of the art and current research. Google scholar is just the kind of database that helps with that. It makes sense to build it for internal use. And given that Google is also good at data analysis, it makes sense to open it up to the public and learn from the usage data. For example: What are hot topics? Which papers are read often in the community? This data can give an extra level of insight into what is going on in the research communities.