So, where are the neighborhoods where humans are already hanging out? Google has a variety of products that while not explicitly “social networks” could easily be thought of as places that help people “share,” a la Facebook’s mantra. Just think about them all: Reader. Picasa. Scholar. Earth. Books. Blogger. Hell, even Zagat. It’s these already bustling communities that should form the core of Google’s next-level social offering. Take Scholar, which allows users to access research papers. A smallish group numbering in the millions visit the site to find research papers because it works better than academic search engines. It’s pretty clear that Google’s corporate honchos think the site is kind of a drag and they have no revenue model for it. Little has been done to update the service, even simple things like allowing people to sort by the number of citations.

How Google Can Beat Facebook Without Google Plus - The Atlantic

Take some time to read Alexis Madrigal’s take on how Google+ could be winning by building social into what already matters.