Welcome to the new logged in search. By rolling out search plus your world, Google is implicitly, but very actively incentivizing users to browse and search while logged in to their Google account.
Google is attempting to create a positive loop phenomenon: the more you engage using Google+, the more useful search becomes, and vice versa.
Will Google succeed in getting users to engage more on Google+? . . . We’ll see.
One key to this question is brand and site owners, who are heavily vested in Google search. One leg of the Google+ strategy must rely on that, and wisely so. As a brand owner, you will want to invest in developing your Google+ page far beyond its current merit as a social network, just to keep your search equity in this new SERP environment. More on that, here.
As a site owner, there are 2 major implications to this change:
Google definitely compromises here, at least in the intermediate period (until Google+ sees the massive sharing that exists on other networks). By promoting so prominently Google+ within search, it might not show useful content from facebook, twitter or otherwise. Arguably, they can’t show most of it anyway because of technical/business/financial limitations, but that might be only half the truth. A new browser tool developed by facebook and twitter engineers, called focus on the user, aims to demonstrate how Google could have been using their content to provide a better social search experience. Google search chief Amit Singhal claims otherwise here.
While the integration of Google+ to search was rolled out to the backlash of numerous and some high profile critics — did you really think that Google would not pull its heavy-muscle Google search, to support its critical goal?
Google, which has prospered, and still does, on the content-centric Web, is now in a phase of transforming itself into a person-centric company. Why?
Because it ultimately improves the online experience and it’s the only way Google can stay fully aligned with the future trends of the Internet. To achieve this goal, risking some now, seems not like such a bad idea.