Google Analytics was hit by an outage that affected some accounts for more than 24 hours, prompting many users to vent their frustration with what they said was Google's unresponsiveness.

Most affected users reported problems on Tuesday and Wednesday last week, although some still experienced problems on Friday. In seemingly all cases, users could access their accounts but found that the Analytics dashboard reported significantly reduced or even zero traffic to their sites.

Google Analytics, a free service, is used by organisations of all sizes, as well as individuals, to track traffic and analyse web site usage. For web publishers, the information Analytics and similar services collect is critical for decisions about their sites' design, content and ad space.

The service was recently described as “not yet enterprise-ready” by an analyst firm.

Vivek Puri, who uses Analytics to monitor his sites StartupSquad and StartupSquad India, suffered an outage of about 24 hours between Tuesday and Wednesday, and about 20 hours between Thursday and Friday.

As disruptive as the service interruption was, Puri felt equally annoyed by what he perceived as Google's lack of communication. It's not the first time he has been upset at Google for this reason.

"They need to inform users when a service is down, and when it comes back up, and give people status updates," Puri said in an interview. "There's no communication from Google about what's going on there."

Indeed, over the past four days, users started at least three active threads regarding this issue on the official Google Analytics Help discussion forum, which is maintained by Google. At press time, Google officials hadn't left a single message in any of the threads.

When asked about the matter a Google spokeswoman acknowledged that there had been a problem. "Earlier this week, there was a reporting delay within some Google Analytics accounts due to system maintenance. No data was lost, and reporting is back to normal now," she said in an email.

She didn't immediately say whether Google informed Analytics users in any way about this system maintenance, before, during or after the work, nor how many users were affected.

Google didn't post any information about this maintenance work, nor the subsequent service disruptions, in its official Google Analytics blog, which, at press time, had last been updated on 21 May with an unrelated posting.

Judging by the feedback from affected users, it seems Google hasn't reached out to them so far regarding this issue. "It would have been nice for Google to inform us about this and to not have had to pull my hair out trying to figure out what was wrong, thinking the problem had been caused by me," said Dean Peters.

Peters, a software company product manager, uses Analytics for sites he maintains as personal projects, including HealYourChurchWebSite.com, and suffered a 12-hour stats blackout on Tuesday.

His frustration is echoed in many of the blog and forum postings.

"Come on Google, after the last couple of days it's time to start telling us what's going on and when we might expect normal service again. How's about a post in the blog at least admitting there's an issue, instead of keeping quiet and pretending everything's fine," wrote a user in Analytics' official Help forum on Friday mornign.

"It would be nice if the folks @ Google acknowledged the problem on one of their many blogs - like say the official Google Analytics blog? A status/outage page would be even better. It's a pain in the ass to have to hunt down groups like this to confirm that you're not the only one suffering from the problem," another peeved user wrote in another thread on the same forum.

Google is a major proponent of the software-as-a-service model, where vendors host the applications that they sell, lease or provide for free to their customers. This business model is an alternative to the traditional packaged-software approach in which customers install and maintain software themselves.

However, one of the big question marks regarding the hosted model involves precisely availability problems, such as the one that affected Analytics this week and that has affected other Google services, including Gmail and Blogger.

"All we want is a dependable service. I know it's free, but that doesn't mean it shouldn't be dependable," Puri said.