The Google+ social networking site saw its traffic and usage drop last week, according to Hitwise.
For the week ending July 23, Google+ received 1.79 million visits, down 3 percent from the previous week, and the average time spent on the site fell 10 percent to 5 minutes and 15 seconds, Hitwise said Wednesday.
By contrast, visits for the week ending July 16 shot up 283 percent from the week before, and 821 percent from the week before that, Hitwise said last week.
As of July 16, Google+ ranked as the 42nd-most-visited social networking site and the 638th-most-visited site overall in the US, Hitwise said last week. Hitwise didn't update those rankings Wednesday, but given the drop in usage it's unlikely that Google+ improved its position on either list.
Google+ is in limited beta release, available only by invitation from current members and from Google, which is limiting access to refine the site and fix bugs before opening it up broadly.
However, a drop in activity is never a good sign for a website, especially a social networking site and one whose launch at the end of June was welcomed with such enthusiasm and buzz.
Hitwise didn't offer an explanation for the drop in Google+'s usage. It's estimated that about 20 million people have Google+ accounts so far.
One key factor for social networking sites to lure new members and get them to use the site often is to foster sharing and interaction among friends.
With Google+, because of the limited availability, it may be that after checking it out and setting up a basic profile, existing members aren't finding enough reasons to return because a critical mass of their friends aren't on it yet.
In the past week or so, Google+ also has weathered a couple of controversies. One centered on Google's decision that people must use their real name for Google+ accounts, which led the company to delete many profiles. That prompted complaints from members who claimed they used their real name and had their account deleted anyway, and from others who argued they should be able to use a pseudonym to protect their privacy.
After the controversy hit a fevered pitch this past weekend, Google pledged to communicate better with affected users and give them a chance to respond before suspending their account.
Another issue revolved around the fact that Google+ only allows profiles for individuals. Many companies have set up business profiles only to see them deleted by Google, triggering more complaints. Google has said that it will allow business profiles within the next few months and that it's working fast to get the site ready for this.
Google+ is an important initiative for Google. The company has high expectations that the site will finally make it a strong competitor in social networking, where it has struggled to find its footing.
Meanwhile Facebook has become one of the world's most popular sites, a situation that makes Google nervous because Facebook keeps a lot of its user-generated content off-limits to the Google search engine.
Facebook also has a tight partnership with Microsoft, one of Google's biggest rivals not only in search advertising but also in other markets, like enterprise cloud collaboration software.
Google trusts that Google+ will prove compelling enough to eventually prompt a massive exodus of Facebook users. In particular, Google believes that Google+ offers privacy and content-sharing features that are better and easier to use than Facebook's.