Facebook users are 64% female (worldwide) according to blogger named Paul Francis who wrote a post titled Exercise for the Reader: Facebook Member Stats:

"…Out of interest I went through the Facebook ad platform to pull together some stats on relative numbers of members from each country. Not surprisingly, the US represents over 40% of the total membership at just over 18 million. Some surprises though (at least to me), with Turkey in 5th place.

There’s quite a heavy bias to the ladies too, with female members making up just over 63% of the total population."

I first read about Facebook Statistics in TechCrunch – Facebook Is Almost 2/3 Women (and other stats) and I found some intersting comments like:

"…Very interesting statistics, that means that just over 20% of Canadians have a facebook profile…. amazing when you think about it 1 in every 5 Canadians have a facebook profile. Compare that to the US with about 6% and the UK with about 11%."

I found some more Facebook Statistics at ViralBlog – Facebook’s Monthly User Growth: 7 million!; also, as the author pointed out Facebook is #4 Website Worldwide according to ComScore.

# Country FB Users Oct FB Users Nov Monthly Growth 1 United States 19,951,900 22,264,820 11.59% 2 Canada 7,361,720 7,866,160 6.85% 3 United Kingdom 6,407,580 7,237,320 12.95% 4 Australia 1,498,320 1,992,280 32.97% 5 Turkey 327,760 1,684,660 413.99% 6 Sweden 827,940 1,017,680 22.92% 7 Norway 891,480 923,720 3.62% 8 France 429,540 802,360 86.80% 9 South Africa 605,820 674,320 11.31% 10 Colombia 359,220 531,900 48.07% 11 Mexico 393,940 485,200 23.17% 12 Egypt 376,480 434,000 15.28% 13 Germany 259,760 389,240 49.85% 14 India 287,500 360,380 25.35% 15 Singapore ze="1">180,660 301,740 67.02% 16 New Zealand 208,000 258,860 24.45% 17 Spain 178,900 232,380 29.89% 18 Israel 94,180 222,380 136.12% 19 United Arab Emirates 188,600 221,700 17.55%

20 Lebanon 163,720 188,960 15.42% 21 Malaysia 98,060 176,520 80.01% 22 Ireland 131,660 171,960 30.61% 23 Italy 121,000 167,980 38.83% 24 Switzerland 99,600 152,900 53.51% 25 Netherlands 109,840 144,400 31.46% 26 China 83,640 139,120 66.33% 25 Saudi Arabia 115,980 137,700 18.73% 28 Pakistan 115,240 128,580 11.58% 29 Japan 95,340 113,540 19.09% 30 Republic of Korea 51,080 59,160 15.82% 31 Dominican Republic. 33,060 39,000 17.97% 42,047,520 49,520,920 Also, it's interesting to note that about 25% of all Social Networking members are in North America, but Asia Pacific actually has more, at 35%:

Threre's a good source of information on WikiPedia that's quite helpful and explains site features as well as having a Facebook Statistics section:

Statistics

(Approximate numbers as of August 2007).^[129]

• Active users: Over 50 million (as of November 2007)^[130]
• Monthly new user average: 4 million
• Daily new user average: 200,000
• Page views: Over 15 billion per month
• Searches: Over 500 million per month^[131]
• Search index size: 200GB
• Largest networks: London, UK^[132]: 1,760,596^[133] and Toronto, Canada: 966,092^[134]

Remaining top 10 countries in order of active users (outside of the U.S., Canada and UK): Australia, Turkey, Sweden, Norway, South Africa, France, Hong Kong.

• Traffic rank: 7th^[6]
• Photos: 1.7 billion (which averages to about 44 photos per user) ^[135]

On March 2, 2007, a poll conducted by eMarketer.com of American youths in the United States discovered Facebook was the most viewed site among all respondents with more females aged 17-25 (69%) visiting the site than males (56%).^[136]

Not that Facebook doesn't have it's own statistics page – Facebook Statistics

Facebook Statistics

General Growth

• More than 55 million active users
• An average of 250,000 new registrations per day since Jan. 2007
• An average of 3% weekly growth since Jan. 2007
• Active users doubling every 6 months

User Demographics

• Over 55,000 regional, work-related, collegiate, and high school networks
• More than half of Facebook users are outside of college
• The fastest growing demographic is those 25 years old and older
• Maintain 85 percent market share of 4-year U.S. universities

User Engagement

• Sixth-most trafficked site in the United States (comScore)
• More than 65 billion page views per month
• More than half of active users return

Also, Trendcatching has a Facebook Statistics page with similar information, if more outdated. 

But, so far, I usually find my information first on TechCrunch – Facebook Users Up 89% Over Last Year; Demographic Shift:

"..Comscore has reported some interesting stats on Facebook, shedding light on the site’s growth after opening up last September and their demographics. Over the past year (May ‘06 – May ‘07), Facebook saw an 89% increase in unique visitors to the site at 26,649,000 uniques, with a 143% increase in page views at 15.8 billion. The site’s stickiness has increased and then tapered off at about 190 minutes per average user."

And I'm finding that I need to keep checks on what's going on in my Facebook network or else I miss out on important events my friends, or friends of friends are doing here in New York.  Before, they used to just post about it in their blogs – no more – it's now done in Facebook, mostly.