Ignore Pinterest as a force at your own peril: women, the 85 percent figure, great photos, and major life events. Cha-ching.

When people talk about social media marketing, they tend to discuss Facebook and Twitter first, and might even get to Google+ (SEO, y’all!) and YouTube and Instagram in front of discussing Pinterest, but … that might be a fool’s errand. Pinterest isn’t for every brand, no — it is predominantly female users, as you might expect, and some brands aren’t attempting to cultivate that (also a fool’s errand, but more on that later) — but now there’s news that the latest valuation of the company is around $5 billion, and people are taking a bit more notice.

It seems like a lot for a site where you pretty much “pin” ideas and themes to different boards, but it’s not even enough — and Pinterest may join that “11-digit club” sooner rather than later. It’s actually pretty simple: the majority of users are female, as noted above, and broadly speaking, women are the driving force behind 85 percent of consumer purchases. Then check out this study: 84 percent of Pinterest users are still active in their fourth year. I was “active” on Facebook in my fourth year there, but mostly hitting like on stuff and occasionally posting myself. I wasn’t pinning the things I wanted in my life or anything (a deeper connection). Then consider this:

Pinterest has absolutely stellar sharing metrics. Sharing on Pinterest grew 58 percent in 2013—faster than it did on Facebook, Twitter, or LinkedIn—according to social data platform ShareThis. Pinterest beats out email as the third most popular sharing platform overall, accounts for 48 percent of all sharing on tablets, and as New York‘s Kevin Roose points out, “drives more Internet traffic to publishers than Twitter and Reddit combined.”

Yep. So combine all these factors:

1. Primary users are female.

2. Females drive consumer purchases.

3. It’s easy to share and people love to do it.

4. User retention is high.

Then factor in this at (5): a lot of Pinterest’s biggest areas involve major life events — wedding, throwing parties, moving into first house/apartment, etc. Brands have been trying to connect back to major touch-points of their consumers since time began; Pinterest almost does it naturally. As TechCrunch points out, Pinterest is about discovery, whereas other Internet giants are about different contextual things — Google being search, Facebook being the people in your life, Google+ being communities of interest, Twitter being events happening in the now, etc. The idea of discovery, though, is very powerful — and for a brand to be at the forefront of that is a strong connection along their arc.

There’s always the chance that the infusion of “promoted pins” — essentially a way for people to advertise on the site / Pinterest to make some money — will turn off some core users (as you may see happening with Twitter a little bit right now — and personally I can tell you that’s happening with me and Facebook), but the growth is clearly there and the underlying factors all line up to make it a success, especially with brands. Ignore it at your own risk. Ahem:

Imagine for a second that you’re a Fortune 500 marketing executive trying to dream up the perfect social network for selling stuff to people. Ideally, you’d want that social network to be filled with women between the ages of 19-39 (since women make an estimated 85 percent of all consumer purchases, and since 19-39 year olds comprise the fastest-growing consumer segment in America). You’d want the network to make it incredibly easy for its users to buy your products, with just one or two clicks. You’d want it to be image-centric and search-friendly. And, crucially, you’d want that social network to put people in a buying mood. You’d want it to be the place where people plan their weddings, pick out furniture for their homes, discover recipes for dinner parties, and plan their outfits. You’d want it to feel less like a social network than an interactive catalog, where users can browse and buy your products, and share the ones they like with their friends. 

This perfect marketing machine you just designed already exists. It’s called Pinterest.