A lot of misinformation about Google+'s male to female ratio is going around Google+ and even being reported on by respectable media sites. For example:
Mashable Headline: Google+ Users Are Nearly All Male
Forbes Blog: Sex Problems at Google+
AdWeek: Google+ Is A Boys Club
All of these articles are based on totally flawed data. Here's why:
Socialstatistics.com is a cool site where G+ users can submit their profile to see if they make the top 100 leaderboard. Shortly after launching, the 87% male, 11% female, 2% other stat started making the rounds. But that data is completely skewed: males tend to compete for leaderboard recognition more than females.
Another great site, findpeopleonplus.com now indexes nearly 948,000 Google+ user profiles and tracks many data points about the users, including gender. They report that of the first 948,000 profiles they crawled, 74.9% are male and 25.1% are female. But crawling is time consuming and the crawlers were finding the mostly male user profiles from the initial field test seeding. This is not a random sampling.
My surname-based random sampling has shown a very different number. For the first time, I'm publishing it here:
7/4 77% Male, 23% Female
7/7 68.4% Male, 31.6% Female (after the user base had almost doubled)
7/14 66.4% Male, 33.6% Female
Google+ is quickly turning pink.
For comparison sake, LinkedIn, which is a business social network with more than 100 million users is still 63% Male and 37% Female according to Pew (See attached report below). Google+'s female population percentage will likely surpass LinkedIn's in early August. The poster of 18 men in a hot tub that has been passed around for the past week or two is not reflective of reality and is not what Google+ is going to end up being.
Google+ is definitely for men, women, and other. (But not kids....yet)