The number of visitors to the federal government's Web site plummeted 88 percent between Oct. 1 and Oct. 13, according to a new analysis of America's online use, while less than half of 1 percent of the site's visitors successfully enrolled for health insurance the first week.

The new numbers on the Affordable Care Act — released by Kantar US Insights, and based on an assessment conducted by the nonpartisan research firm Millward Brown Digital — provide a snapshot of how the federal health-care exchange has fared since it launched at the start of the month.


Based on a sample of two million users — or 1 percent of all online users in the U.S. — which Millward Brown Digital has permission to track, it suggests that the rush of traffic administration officials cited as the cause of the site's problems trailed off within a matter of days.

Of the 9.4 million unique visitors to the site during the launch's first week, according to the analysis, roughly a third attempted to register, and a third of that number — 1.01 million — completed registration. Ultimately, roughly 36,000 Americans signed up for an insurance plan online, the report said.

The image above shows the declining numbers of participants who progressed through the site's different stages.

In an e-mail, Health and Human Services spokeswoman Joanne Peters challenged the idea that traffic had dipped as much as the analysis suggested.

" received 14.6 million unique visits in the first 11 days, showing the intense demand for quality, affordable health insurance," Peters said. "While traffic is down somewhat from its peak on day one, it remains high as Americans continue to seek to learn more about their new coverage options.  We will be releasing enrollment figures on a monthly basis similar to how we release data for the CHIP and Medicare programs."

An administration official who asked not to be identified because enrollment figures have not been published said the numbers in the Kantar US Insights report were "inaccurate.

And Aneesh Chopra, who served as the White House's first-ever chief technology officer during President Obama's first term, said the analysis actually captured the public's sustained interest in signing up for health insurance on the federal exchange. He noted that while the total number of visitors to the site is interesting, it matters much more that one million Americans created an online account.

"Account creation is always the holy grail. That’s the moment that matters," Chopra said in an interview. "In one week, a million people began a process that will result in affordable coverage. That means a lot of people are going to ultimately get the product."

In a blog post, Millward Brown Digital Vice President Matthew Pace, who called the first week's performance "atrocious," noted that the numbers could change dramatically once the federal government improves how the Web site functions.

"The fact that millions of Americans not only visited the exchanges but also took what actions they could to register and enroll suggests that demand indeed exists for new healthcare options," Pace wrote." As the site improves and more consumers are able to compare their coverage options, they'll decide with their wallets how truly affordable Obamacare turns out to be."

At the moment, Americans' interest in logging on has dropped sharply from the time of the launch. In an interview, Pace compared the initial number of users to the kind of traffic experiences, noting that about 0.9 percent of all online users logged onto during the first week. As of Oct. 13 that reach had declined to 0.1 percent, he said. Last week, he estimated, the site attracted 4.1 million visitors, or less than half of what it garnered during its first week.