Google+ has opened a public "pages" feature on its social network for businesses, and has already attracted brands such as Burberry, Save the Children, Mumsnet, the Muppets and O2.
Until now, only individuals have been able to have a profile on Google's social networking site, launched just over 100 days ago.
With the new pages feature, businesses will be able to create their own profiles, enabling Google+ users to comment directly on the company or product and to add their endorsements.
The internet firm said the Google+ pages facility, which is being offered free of charge and free of Google advertising, will help companies and campaigns engage with their audience.
The move is a further challenge to rival network Facebook, which offers its own pages service to businesses, according to the BBC.
Organisations will be able to link from Google searches or Google ads through to their Google+ pages and monitor how many people are linking through and from what.
This is what makes Google+ different from other social networks, the company said, as well as its deep integration with YouTube.
Launching the service, Google sought to allay privacy concerns by announcing it will not pass on individual IP addresses or any other personal data.
Organisations will be able to use the site's Circles facility to match different information to different groups and set up video chats using the network's Hangouts service.
Google has also launched Direct Connect, a service which enables users of the Google search engine to connect to an organisation's Google+ page by simply typing '+' ahead of the group's name.
Despite the rapid growth of Google+ it has a lot of catching up to do before it can compete with Facebook, which currently has around 20 times as many members.