Google's social network Google+ set off to a roaring start within its first month of inception, but new data is showing that visits to the site are slowing down, highlighting the challenges Google faces as it vies for space in the competitive social media market.

The new site received more than 1.79 million total visits during the week ending July 23, representing a three percent decrease from the week before, Web analytics firm Experian Hitwise found.

Additionally, the time spent on the site also decreased, with users spending an average of 5 minutes 15 seconds on Google+, down 10 percent.

The new findings highlight the challenges that Google faces as it attempts to break into an already crowded social space.

Google needs to take steps to ensure that its new social network doesn't follow the same fate as its predecessors: Google Buzz and Google Wave.

While those sites saw initial interest, participation waned and those projects were eventually pulled.

"[Google+'s] ultimate success will depend on how well it converts this strong trial base into regular users," ComScore's Andrew Lipsman warned.

Indeed, while rivals like Facebook and Twitter have become online destinations in themselves, over 50 percent of traffic coming to Google+ originates from Google or Gmail. Google's video site YouTube was also a large referrer.

Facebook also enjoys stronger user engagement than Google+. In the increasingly competitive digital marketing environment, advertisers are concerned with not only reach and targeting, but also user how long users are interacting with the site.

HitWise Research Director Heather Dougherty said the average visit time for Google+ last week was 5 minutes and 50 seconds, compared with almost 22 minutes users spent on Facebook.

And while Google CEO Larry Page told investors that the site has already amassed 10 million users, HitWise data indicates that not nearly that many people are coming to the site, on average.

The 1.79 million visitors from the U.S. that came to the site last week represent just 10 percent of those registered.

With strong integration to Google's ecosystem of products and services and plenty of hype, Google+ has shown it has no problem attracting new registered users.

The challenge will converting them from passers-by to dedicated users.