Fledgling social network Google+ has had a recent traffic boost, recording its third-largest week of visits since the site launched in June, according to online traffic monitor Experian Hitwise.

The social network had more than 6.8 million US visits in the week ending 12 November. That's a 5 percent increase compared to the week before and a 25 percent increase compared to a month ago, according to Hitwise.

"This tells us that Google+ is starting to catch on," said Zeus Kerravala, principal analyst with ZK Research. "I think Facebook has gotten so big and some people are so annoyed with their security issues that people are starting to seek an alternative."

Now that Google + has more than 40 million users, people are finding more friends and colleagues on the social networking site than they were when it launched last summer.

"Well, 40 million users are still a ways off of Facebook's 800 million, but it's still a big number," Kerravala said. "It's big enough that when you join Google+, there are people there to find."

Hitwise reported that the number of returning visitors has been rising this month. The average number of returning users in the first two weeks of November compared with the first two weeks in October jumped 18 percent. For the week ending 12 November, 74 percent of Google+ traffic was from returning visitors.

Hitwise also noted that Google+ users are spending more time on the site. The average visit time rose 15 percent in October compared with the month before.

That shows a growing "stickiness" that Google+ will need to be successful, Kerravala said.

On Wednesday, Google unveiled its Google Music service and immediately integrated it with Google+ so users can share music for free with the friends in their Circles. That kind of integration also makes people quicker to return and to spend more time on the network.

"The more people who join Google+, the stickier it gets," said Kerravala. "It's this whole community of friends thing. The bigger the community, the stickier the site gets."