This past week Microsoft released Silverlight 2. While Silverlight 1.0 focused principally on online video applications, Silverlight 2 is the first version of Microsoft’s cross-browser runtime environment that serves as a fully expressive platform for developing rich Internet applications (RIAs).

What we now know as Silverlight 2 was originally announced as Silverlight 1.1, but the feature set was sufficiently advanced relative to Silverlight 1 that Microsoft decided to dub it version 2. That PR-based numerical legerdemain has now been followed by a slew of fuzzy statistics in Microsoft’s Silverlight 2 press release.

As with Internet search, Microsoft is playing catch-up in the cross-platform RIA space. In this arena the incumbent is not Google but, rather, Adobe Systems. According to numbers cited by Adobe based on a Millward Brown survey conducted in June 2008, that company’s Flash Player is installed on 99.0 percent of Internet-enabled PCs “in mature markets” (the later defined as including the U.S., Canada, U.K., France, Germany, and Japan).

Microsoft realizes that reaching ubiquity — or, at least, a sufficient “tipping point” where one can assume that most users have the runtime environment installed — is critical for success. Their press release announcing Silverlight 2 contains a number statements regarding how widely the Silverlight platform is deployed, starting with the title: “Microsoft Releases Silverlight 2, Already Reaching One in Four Consumers Worldwide.” But the numbers in the release provide little insight into the actual penetration of Silverlight on computer systems.

The “one in four” number comes from a quote in the release from Microsoft corporate vice president Scott Guthrie who states, “We launched Silverlight just over a year ago, and already one in four consumers worldwide has access to a computer with Silverlight already installed.”

It was one year ago that Microsoft launched Silverlight 1.0. So Guthrie’s quote presumably pertains to any version of Silverlight, not the various beta versions of Silverlight 2 (just as Adobe’s 99% figure includes all versions of the Flash Player). But the headline “Microsoft Releases Silverlight 2, Already Reaching One in Four Consumers Worldwide” blurs the distinction about which versions are being referenced.

Perhaps more significant is the precise wording of Guthrie’s “one in four” statement. The statistic refers to the number of consumers who have “access to a computer with Silverlight already installed.” Some commentators have taken this has indicating a penetration of 25 percent in a manner comparable to the Adobe statistic. But others, such as the Seattle Times’ Ben Romano (via Ryan Stewart), note that Guthrie’s words imply that Microsoft and Adobe are using different measures.

Adobe’s number specifies the percentage of computers with Flash installed. Microsoft is measuring percentage of people with “access to” Silverlight. Since many individuals have access to multiple computers — at home, at school, at their business — this latter statistic doesn’t tell us much about the relative penetration of Silverlight on computers.

There are more fuzzy numbers in Microsoft’s release. In the next paragraph the release states, “Silverlight adoption continues to grow rapidly, with penetration in some countries approaching 50 percent….” This naturally raises the question: Which countries? The U.S.? Canada? China? Luxembourg? Vatican City? It makes a difference.

More detailed numbers follow but provide little perspective on the depth of Silverlight adoption. We read that during 2008 Olympics Games in Beijing, NBCOlympics.com “had more than 50 million unique visitors” (although we don’t know how many had Silverlight installed). The “70 million video streams and 600 million minutes of video watched” would have required Silverlight, but we don’t know how many streams were viewed per user, so we don’t know the number of unique viewers with Silverlight. Even if we did know the percentage of users with Silverlight on the Olympics site, this would not be a representative sample Internet users or computer systems.

The relative measure cited for the increase in Silverlight deployment as a result of the Olympics coverage —  “Silverlight market penetration in the U.S. [increased] by more than 30 percent” — isn’t helpful unless you know the base number of systems with Silverlight before the increase.

All of this number juggling indicates how important distribution is to the success of an RIA runtime environment. Microsoft, no doubt, will persist until Silverlight is widely available on Windows and Mac (and maybe Linux) computers. But how far they have yet to go to achieve this is unclear at present.

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