Social networking platform Meebo also took a hammering, coming in third. Meebo is essentially a platform incorporating several instant messaging servers.
"Together with Google, we're super jazzed to roll up our sleeves and get cracking on even bigger and better ways to help users and website owners alike," Meebo wrote Monday on its blog.
A Google spokesman said the company is always looking for better ways to help users share content and connect across the web, as in daily life.
“With the Meebo team's expertise in social publisher tools, we believe they will be a great fit with the Google+ team,” the company said.
"We look forward to closing the transaction and working with the Meebo team to create more ways for users to engage online."
Terms of the acquisition were not disclosed. But tech blog All Things D first reported rumours about a Google-Meebo acquisition in May with an alleged asking price of about $100 million.
Meebo has raised $70 million in venture capital since its inception in 2005.
Google Inc. has spent more than $16 billion buying 140 companies since the end of 2009. That includes the biggest deal in Google’s 14-year history, a $12.5-billion acquisition of cellphone maker Motorola Mobility.