Semantics. Usually technology companies keep products in beta for a short period of timeas a transitional phase between "alpha" (when in-house testers or focus groups try out the software) and the official release. Beta releases also tend to be more buggy than the final version. Neither of these qualities accurately describes Gmail (although there was a worldwide service outage in February); the label is just a way for Google to signal users that they're still tweaking the e-mail service and adding new features. Company spokespeople won't say exactly when Gmail will be out of beta, but apparently there's an "internal checklist" that's lacking in some crucial checkmarks.
Google has decided to leave its product in beta rather than issuing updates in the familiar system of numbered software versions1.0, 2.0, and so on. Those distinctions make more sense when tech consumers are purchasing software on CD-ROMs or downloading it onto their hard drives. The Google take is that the beta label better conveys the "constant feature refinement" consumers expect from Web-based applications. Of course, the end of Gmail's beta era won't signify the end of feature updates, so for anyone who isn't on the Gmail product team at Google, the distinction means very little. In fact, it may just be a marketing ploy to give Gmail a cutting-edge feel. Even co-founder Larry Page once admitted that using a beta label for years on end is "arbitrary" and has more to do with "messaging and branding" than a precise reflection of a technical stage of development.
A lengthy beta phase is not exclusive to Gmail. As of September 2008, almost half of Google's products were in beta, including Google Docs and Google Finance. Google News was in beta from its launch in April 2002 until January 2006. (When the Google News creator, Krishna Bharat, announced the change, he noted that the news team had successfully made the product more personal, with e-mail alerts and the option to create personalized pages.) Beta lag is not exclusive to Google, either: Flickr launched in February 2004 as a beta product and retained the label even after Yahoo acquired it in 2005. Then, in 2006, Flickr updated from beta to "gamma"a sly joke to indicate that the service is always changing.
Apple deploys the beta label in a more traditional fashion. In March 2008, for example, the company made iPhone 2.0 beta software available to select developers and customers. That July, it officially rolled out the update for the general public. And Google doesn't always let its products dither in beta for years on end. The company dropped the beta label from its Chrome browser after just 14 weeks; and the Google search engine spent less than two years in beta after being released in 1997.
The tech community is divided on the issue of protracted beta releases. A ZDNet article from 2005 called out Google and Flickr for extended use of the label and noted that the practice could blur the line "between prime time and half-baked." Tim O'Reilly, the open-source advocate, has used the term perpetual beta positively as an indication of open-source development processes wherein users are "treated as co-developers."