The number of visits to Google’s social networking service service Google+ in teh US surged 14 times last week afetr the company opened the service to the general public, according to online tracker Experian Hitwise.

Last week, the search engine company opened its social networking service to all and also added new features such as search in it.

Google had said in an official blog that after 12 weeks of testing, Google+ was ready for its beta release. Earlier, during its field trial, people needed an invite to join the network.

Company senior vice-president of engineering Vic Gundotra had said, "For the past 12 weeks we’ve been in field trial, and during that time we’ve listened and learned a great deal."

"We’re nowhere near done, but with the improvements we’ve made so far we’re ready to move from field trial to beta, and introduce our 100th feature: open signups. This way anyone can visit google.com/+, join the project and connect with the people they care about," added Gundotra.

Now according to Experian Hitwise, the Google+ site received almost 15 million US visits in the week ended 24 September compared with 1.1 million the previous week.

Chief rival Facebook has made several improvements since Google launched its new social networking service in June. Recently, Facebook improved its privacy settings, added "smart lists" and joined hands with Twitter to link user accounts. Co-founder Mark Zuckerberg also announced a major redesign of its user accounts in the f8 conference.

Google’s strategy seems to be reliant on its other services such as Maps, YouTube and search.

Gundotra revealed in the blog that Google+ will borrow another feature from Google search. This time it is the popular search feature itself that will be embedded in the network. Recently, Google added +Snippets from its Maps service to the social networking service.

"You’ve been asking for it, and we’ve been busy building it, so today we’re bringing Google’s search expertise to Google+. Just type what you’re looking for into the Google+ search box, and we’ll return relevant people and posts, as well as popular content from around the web." said Gundotra.

The company hopes to leverage its search feature to increase members in the social networking service.