Market share of audio based formats including QuickTime, WMA, MP3,
realmedia, etc. Preferably Worldwide broken down by country, however
my main interest is the US?

Lochradio --

Two companies track web statistics in detail: A.C. Nielsen in its Net
Ratings and Comscore in its Media Metrix studies.  Some interesting
overall numbers are available on their websites -- and if you require
more information, both companies have both standard and custom data
available for clients:
A.C. Nielsen
Net Ratings Data (by country)
http://www.nielsen-netratings.com/news.jsp?section=dat_to&country=us

Comscore
Media Metrix Description
http://www.comscore.com/metrix/


Occasionally the measures that are provided make their way into the
public domain.  This French site notes that in June, 2002, the
worldwide market shares for all versions of each player were.  Note
that increasingly each of the media players runs multiple formats,
though Winamp (from Nullsoft, now owned by AOL) is closely associated
with MP3s.  The data's taken from Comscore numbers:
Realplayer:  30.8 million
Microsoft: Windows Media Player: 30.1 million
Apple Quicktime: 12.3 million
Winamp: 7.9 million
Musicmatch Jukebox: 7.3 million

Le Journal du Net
"Multimedia players in the world" (Sept. 5, 2002) -- translated
http://solutions.journaldunet.com/dossiers/indicateurs/intranet_extranet/videoplayer_monde.shtml

At about the same time, there was quite a bit of debate on HOW these
share measures were being done.  This C/NET article has excellent
detail on share and share measurement:
C/NET
"Statistics Firms Revisit QuickTime Counts" (Olsen, June 19, 2002)
http://news.com.com/2100-1023-937302.html

Later in the year, right after the federal court decision by Collen
Kollar-Kottelly, market shares for a variety of Microsoft products
were listed.  In this instance, the source gives WMP 14.4% of U.S.
homes, versus 16.2% for Realplayer:
Network World 
"Judge Reaffirms Limited Microsoft Punishment" (Weil, Nov. 2, 2002)
http://www.nwfusion.com/news/2002/1101msverdict.html

As you're probably aware, at the end of 2003, Real Networks (NASDAQ:
RNWK) filed suit against Microsoft for antitrust violations in Santa
Clara, CA.  It has also been pursuing action against Microsoft in the
EEU for bundling of Windows Media Player with the Windows operating
system -- which accounts or 93-95% of all personal computers shipped. 
One could anticipate that the lawsuit and enforcement actions were
taken to forestall growth by Windows Media Player.

Putting a current share on applications, Rob Greenlee gets updated
numbers from Nielsen's Abba Bhagat:
WebTalk Guys Radio Show
"Top Internet Trends for 2004" (undated)
http://www.webtalkguys.com/10604.shtml

Windows Media Player: 34%
AOL Instant Messenger: 20%
Real Player: 20%
MSN Messenger Service: 19%
Yahoo! Messenger: 12%

Google search strategy:
Comscore + "media metrix" + "Windows media player"
"Nielsen net ratings" + "Realplayer"
"market share" + "Windows media player"

To get more recent data from the last 90 days -- or news stories
regarding Real Networks' action in the courts or EEU, you might want
to do similar searches at Google News:
http://news.google.com/

Best regards,

Omnivorous-GA

---

Clarification of Answer by omnivorous-ga on 09 Feb 2004 09:48 PST

Lochradio --

There was one other place that I'd looked for share data that may be
important to you.  Knowing that you're looking at the entire area of
Internet radio, you might find Real Networks' recent analysts call
interesting, particularly Rob Glaser's comments on the company's shift
to consumer media services.  It's linked here from their Investor
Relations page:
http://www.realnetworks.com/company/investor/index.html

I'd scanned RNWK's financial information for share information but
didn't see anything of value there.

Best regards,

Omnivorous-GA

Thanks for the quick information!