More than 7 million Americans have gone online since Tuesday to browse the Obamacare health insurance exchanges, prompting HealthCare.gov administrators to add servers and engineers to handle the Web traffic.
Another 295,000 people used federal health insurance exchange call centers and 167,000 have requested live Web chats, according to Centers for Medicare and Medicaid Services spokesman Richard Olague.
"Experts are working around the clock and were able to expand system capacity somewhat overnight, cutting by one-third the volume of people waiting to apply," Olague said in a statement to ABCNews.com, adding that call center wait times have also been cut in half since Tuesday to roughly two minutes. "Work on the site continues today to meet the demand and excitement generated in just the first 48 hours of our open enrollment."
Although the marketplaces were spared from federal furloughs, a surge in Web traffic has been blamed for frustrating lags and error messages throughout the day. Americans trying to scope out their options at HealthCare.gov are instructed to "please wait" for the login page, which can take several minutes to appear.
"We have a lot of visitors on our site right now and we're working to make your experience here better," the site message reads. "Thanks for your patience!"
Health and Human Services Secretary Kathleen Sebelius warned Monday that "glitches" would be inevitable, comparing it to Apple's latest software upgrade.
"No one is calling on Apple to not sell devices for a year, or to get out of the business because the whole thing is a failure," Sebelius said, referring to a move by Republicans in the House to postpone the implementation of Obamacare by a year. "Everybody just assumes, 'Well, there's a problem, they'll fix it, we'll move on.'"
State-run insurance exchanges have also grappled with Web and call center volume, causing sluggish sites and long phone wait times. But overall, the launch of Obamacare has been viewed by many site administrators as "successful."
"The amount of interest we've seen and the way that the system is functioning overall, we're very happy," said Ben Davis, a spokesman for Colorado's marketplace Connect for Health Colorado, which has drawn more than 107,000 online visitors since Tuesday despite displaying intermittent error messages.
Roughly 8,400 Coloradans have created accounts to purchase a plan, according to Davis. And Colorado "navigators" – helpers charged with steering shoppers through the purchasing process – have fielded more than 6,400 live chats and calls since Tuesday.
"The first two days of operations at Connect for Health Colorado were full of activity, with thousands of consumers visiting our website and calling our customer support network," Connect for Health Colorado CEO Patty Fontneau said in a statement. "While there have been some challenges, we are pleased to see that Coloradans are looking at their options, shopping and signing up for health plans."