The Google+ social network could be about to hit the 10 million member mark, despite currently being in a 'limited field trial'.

Google hopes the social network, which was launched at the end of last month, will rival Facebook's popularity by letting consumers share photos, chat to each other and leave messages and comments.

Furthermore, the social network benefits from Circles, which lets users create lists of friends to share content with, as well as live video-chat for multiple users known as Hangouts, Huddle - a form of group instant messaging - and Sparks, which lets users interact with others that have similar interests.

However, Google+ is only available to a select few web users, although those that have been given access to the site can invite other web users to join.

Paul Allen, the founder of, attempted to estimate the number of users that have signed up already.

"By using a sample of 100 to 200 surnames, I am able to accurately estimate the total percentage of the US population that has signed up for Google+," Allen said in a post on Google+.

"Then I use that number and a calculated ratio of US to non-US users to generate my worldwide estimates."

Google has yet to release official figures on the number of members the social network has.