Image caption The Circles feature in Google+ allows members to categorise friends into groups

Google+ was supposed to be a "Facebook killer". Some now say it's already dead - but the search giant says it is just getting started.

The 19th Century writer Mark Twain once famously told a newspaper journalist: "The report of my death was an exaggeration," following unfounded media speculation that the author had suffered a fatal illness.

Similarly, search giant Google, which unveiled its much-anticipated online social network Google+ at a private launch in June, is battling recent reports from pundits who claim the network is "dead".

Early reports wagered that the service would one day rival social network Facebook in popularity. But a mere four months later, grim headlines have begun popping up on the homepages of US media outlets.

Forbes published "A Eulogy for Google Plus", while Slate declared simply: "Google+ is dead".

In contrast, though, social media news blog Mashable said the new service may still emerge as a significant force in the online world.

The online tool gained 10 million users within the first 16 days after its private launch, and 40 million within the first 100 days, making it the fastest-growing social network in the history of the web.

Facebook and Twitter both took more than two years to hit the 10 million user milestone.

But web analytics firm Chitika reported in October that excitement appeared to have waned for Google+ one month after its public launch, with traffic down 60% after spiking to 1,200% of pre-launch levels.

We have not even begun, let alone these reports of premature demise Bradley Horowitz, Google+ Google to kill off more products

Google has not released figures on the number of users signing up since mid-October.

Meanwhile Facebook, which now boasts more than 800 million users, has unveiled features similar to those that once set Google+ apart - such as the ability to lump friends into groups in order to separate who sees which content.

Reporting for Forbes, Paul Tassi was clear about the challenge Google faces trying to compete with Facebook.

"No-one is going to scrap a social network they've spent eight years building up to start over from scratch for one that offers only a few minor improvements," he wrote.

'Social layer'

Bradley Horowitz, vice-president of product at Google+, says the service aims to be more than simply a social networking website.

"Google+ is a foundational element for identity, relationship, interest across all we're doing at Google," Mr Horowitz tells BBC News, adding that the social networking function is just one of many social tools.

Media playback is unsupported on your device Media caption Google's Bradley Horowitz on the decision to delete Google+ business pages

Mr Horowitz says Google is attempting to build a social layer across all its products - including Gmail, YouTube and Blogger - in an effort to help tie the services together.

For instance, Google+ users can recommend links, videos and other pieces of content to their friends by clicking "+1" on a small widget, Google's version of the Facebook "Like" button.

This +1 is then used to help inform Google about how to list results from search criteria for each user.

"Everything we do is going to be informed by this sense of person and interest and relationship, so that all users' data can be used in their interest at their discretion," Mr Horowitz says.

"So the concept of Google+ dying, it's a misunderstanding of what we're doing," he says. "We have not even begun, let alone these reports of premature demise."

John Abell, New York Bureau chief of Wired.com, agrees with Mr Horowitz, but adds that Google+ could conceivably grow alongside Facebook, rather than in competition with Mark Zuckerberg's empire.

Mr Abell told BBC News that online communities were maturing and had "entered an era where there will not be a single dominant social network that kills the previous one, which has been the history of social networks so far".

And he says that if any company can build itself up as a social superpower alongside Facebook, it is Google.

"We're not talking about somebody who has borrowed $10,000 from his mommy," Mr Abell says. "This is Google."

"Since Google has such deep pockets, the notion that you can declare it dead because you are counting numbers and trend lines on a spreadsheet is kind of loopy."

Major player

Google has partly built its reputation on the breadth of its services, from email to photo sharing to music streaming. Users of these products total in the hundreds of millions, comparable figures to Facebook's reach.

But Google's bedrock still remains its search engine, which has been challenged by the increasing trend of online users finding content through their friends rather than through search.

Whether Google+ grows or not, the public should expect to see Google putting everything it has into the service's promotion and development during the coming months.

After all, many people first learned about Google+'s reported demise through friends - on Facebook.