By now we all know the power of the online female consumer. She propelled Pinterest to lofty, billion dollar heights, she is the dominant user on Facebook, and she drives the conversation on Twitter.

The female consumer is the decision maker behind a whopping 85% of all brand purchases. In fact, her spending habits propelled Pinterest to deploy an analytics platform this week meant to leverage the buying power of users for the companies that covet those dollars. However, a recently spotted trend amongst the female consumer base may indicate that social media is still rapidly changing, and that more focused, niche networks will see greater engagement in the future.

According to research recently released by KCR Research, nearly four in 10 North American women (38%) have decreased or stopped their usage of one or more social networks during the past six months. (See Infographic)

“We believe that these findings reflect the importance of time management in women’s lives and their empowerment to control what networks provide them with the most personal ROI.” Says Marcy Massura, Director of Digital Engagement at Weber Shandwick. “As women become even more efficient in how they manage their busy lives, they will increasingly apply those skills to their social networks. The churn that our study identified seems to indicate a preference to ‘go deep’ in fewer platforms, versus being spread thin over many.”

Prior to the rise of Pinterest, a number of web 1.0 social networking sites had successfully grabbed the interest of women. Sites like CafeMom and iVillage generated massive page views through an engaged audience that was looking for ways to connect with other women on topic specific discussions.

More recently, women have quickly and widely adopted the Web 2.0/social media sites that allow users to create and aggregate their content. However, these large, flat platforms do not necessarily lend themselves to a focused use.

Women do not have a lot of time. The time they spend online needs to be both entertaining and useful. For the large platforms such as Pinterest this means upstart sites like Lover.ly (where users collect and share wedding visuals) are a serious potential threat.

“Niche sites offer value to a woman in ways more general platforms may not,” adds Massura. “Since the niche platforms generally come with a specific theme or topic, she is free to engage deeply and frequently on one of her prime interests. What is important to her is that the quality of engagement can be more personal on niche sites and even message board communities than what she may get on more public broad-sweeping platforms. She can also confine her time to a topic she cares about instead of weeding through more extraneous commentary. From a marketing standpoint, smaller community sites offer wonderful opportunities to connect with her in more meaningful ways.”

While industry reports of teens pulling back from their Facebook engagement have been widely reported, they are perhaps not as alarming as the fact that the people who hold the purse strings of economic growth are narrowing their online focus. For tech investors hoping to stumble onto a young site with potential for both user base growth and legitimate possibilities for income stream generation, it seems as though tracking women’s online activities would be priority number one. But, sadly, except for a very few, it is not.

Find that hard to believe? Ask the Pinterest team, who pitched to many potential investors and found no interest early on in their lifecycle, even though the site had an established, engaged user base right from the start. Or, ask the team at The Muse, who recently shared their difficulties in raising funding for a site that is focused on a female user base, and also had very solid engagement numbers early on.