"The more prevalent and important Google Apps like Gmail become, the more negative attention each outage will garner - much to Google's embarrassment and chagrin," said Dan Olds, an analyst at Gabriel Consulting Group.
"Email is a mission-critical application for business users. If customers perceive that Gmail isn't reliable, they won't adopt it. Every Gmail outage makes companies think twice before adopting the free email solution," Olds added.
Last week's worldwide Gmail outage was caused by a server traffic jam, according to Google's official Gmail blog.
"We had slightly underestimated the load which some recent changes placed on the request routers," Ben Treynor, a Google site reliability czar, said in the blog post.
"A few of the request routers became overloaded and in effect told the rest of the system [to] 'stop sending us traffic, we're too slow.' Within minutes nearly all of the request routers were overloaded."
Gmail engineers were alerted within seconds of the outage and, after figuring out what the problem was, brought additional request routers online, Treynor said. Within 100 minutes, Gmail was more than 99.9 percent available to users, he added.
"We've turned our full attention to helping ensure this kind of event doesn't happen again," Treynor wrote.
Matt Cain, an analyst at research firm Gartner, suggested that Google could avoid such outages by using separate infrastructures for corporate and consumer Gmail users.
"Google must prove that consumer and commercial services are largely independent of each other, and that the commercial services will sustain at least a 99.9 percent uptime, which is the standard for most commercial email SaaS services," Cain said.
"The critical issue for Google is to segment commercial Gmail traffic from consumer traffic," he said.
Google still maintains that the service is inherently more stable than competitive on-premises offerings, such as Microsoft's Exchange e-mail server and IBM's Lotus Notes collaboration software.
See also: Gmail suffers second outage this year