Most of us don’t get to choose what we write about. Your new client makes pollen-resistant underwear? Congratulations. You’re now an author specializing in allergen-repelling undergarments.

This setup sounds pretty funny until you have to write 15 blog posts per month for PollenProof™’s new marketing campaign. The idea well runs dry pretty quick. How do you keep your interest peaked and idea generator fresh? Random affinities to the rescue!

Random affinities

This term is 100% made up by me with a lot of help from some colleagues. I’m not so worried about protecting it – just beware that if you decide to use it and get laughed out of the room, your only reference is a sweaty, pale marketing guy who spends his spare time training his cats to play fetch.

Two topics have ‘random affinity’ if they are connected only by a common audience. For example: the fact that I like cycling may mean I’m four times more likely to watch "Adventure Time." There’s no subject connection between cycling and "Adventure Time" - Jake and Finn never ride a bicycle. The only connection is the fact that an unusual number of people are interested in both.

A few other (potential) examples:

• Cyclists are more likely to own tablet computers.
• Cyclists worry more about skin cancer and skin protection.
• People who belong to a PTA or PTO are more likely to be aquarium or zoo members.
• People who attend boat shows are more likely to watch extreme sports on TV.

Don’t overthink it. Two ideas + no obvious connection except audience = random affinity.

So what?

This is the part where you say: So what, Ian? You writing a new book or something? Why are you wasting my time with all this fake academic marketing crapola?

The answer is this: random affinities are another way to attract and keep your long tail audience. I don’t buy a bicycle every month (not for lack of trying). I buy one every few years. You can try to catch my attention at just the right time for a bike purchase. But you’ve got a better chance of selling to me if you catch and hold my attention throughout my bicycle buying dry spell. You can do that by speaking to the random affinity topics I like. I’m over 30, plus I sunburn under full spectrum lighting, so skin protection is pretty important to me when I ride. I own a tablet computer, as well. And, if you occasionally talk about "Adventure Time," there’s no question that I will remember your company when I head for the local bike shop for my next toy.

Use ‘em right, and random affinities can increase your likelihood of:

• Building rapport with potential customers
• Helping folks remember you
• Giving you something to write about besides pollen-proof skivvies

Company and sanity savers. They’re dang handy.

Finding random affinities

Way back before the Internet, when I lived in a rolled-up newspaper and got paid in fish heads, we found random affinities by a) guessing, or b) interviewing random people and hoping they weren’t screwing with us. Times were tough.

With the Internet, tools are abound. You can’t click a link without knocking one over. Here are a few of my favorites for finding random affinities:

First, use your brain. This is marketing. After conducting all the math and pretending we can computerize it all, it’s still about looking at the product, looking at the audience, and seeing the connections. Don’t treat these tools as automatic marketing machines. If you come crying to me because you got fired after you tried to sell granola bars with articles about camel spiders, I’ll just laugh. And probably write about you.

Facebook Ads are my #1 source. Sign into Facebook, then select Create An Ad. It doesn’t matter what your first ad is about; you’re just using it as a tester. Then, scroll down to ‘Precise Interests.’ Start typing, and pick the interest that makes the most sense. You’ll see a list of suggested likes and interests:

Explore to your heart’s content. Keep in mind that Facebook might not always help your exploration, so be sure to keep it creative. I once searched for "yurts" and found nothing. That’s OK, keep searching! Moving on to the next tool...

Amazon.com is a freaking gold mine. Go search for the top books on your topic. Then scroll down to "Customers who bought this item also bought." It saved me when I was yurt-hunting. Apparently a lot of yurt shoppers also care about composting, ergonomic furniture, getaways, and my favorite, alpacas:

There are some loose semantic connections here, but if you’re yurt-impaired like I was, these are great new topics. I’m not sure many people would make the connection between yurts and ergo furniture. And while I might picture alpacas frolicking about my yurt, I wouldn’t have considered them potential topics.

Google suggest can sometimes help you connect unexpected subjects that are linked by audience questions. I could write a lot of articles about this one:

Though I have to admit, the question alone pushes yurts down on the list of Future Places Ian Might Live. **Shudder.**

Reddit is fantastic. Take a look at the subreddits for any topic:

I never would’ve thought of Burning Man. Or Occupy Wall Street, for that matter. These aren’t really random affinities, but the search sure helped me come up with more material. And, I can now search Burning Man random affinities to find even more to write about. Evaporative air conditioners, anyone?

If your site, or any other relevant site, or any of the sites dealing with any of the random affinities you found get a decent amount of traffic, the DoubleClick Ad Planner can help you find even more. I searched the Burning Man web site in the Ad Planner and found some pretty useful stuff. First, and article or three about photo sharing and photography might be worth testing:

It’s possible yurt fans look for concerts more than the average person, too:

I’ll see what I can dig up about musical interests for my audience and test a few articles about best soundtracks for life in a yurt.

If you’re not saying what the hell, you’re not doing it right

Alpacas? Concerts? Desert events where visitors sunburn their unmentionables? It all seems… random. Right? Exactly. Truth is that the yurts example is a little bit on the fringes of the mainstream consumer audience. Try bigger B2B and B2C topics and you’ll get even better, harder-to-find random affinities.

Is it working? Getting buy-in from the boss

Your boss doesn’t care about your creative genius. She’ll just want to see the money. Or the stuff that’ll turn into money. So make sure you look at the data. I wrote a piece about Dungeons and Dragons and marketing, way back when. Affinities don’t get much more random. When it comes to short-term traffic, it sure worked:

My success metric is sustained growth, though. Zooming out a bit more, it looks like I got a nice surge that lasted for at least a few weeks:

Visitors even stuck around to read the whole thing:

If I were padding anything except my ego, I’d look at sales and other conversions, too.

Of course, before you can even write, you’ve got to convince your boss this is a good idea. Be super-clear. Show her the audience overlap. I’ve found CMOs and similar to be really receptive to random affinity marketing because it fits with traditional best-practices so well. One suggestion before you begin: start with milder stuff. Don’t sell yurts with Burning Man photos if you can do ergonomic furniture. Move on to the photos after you’ve proven the concept.

No autopilot

Again, this strategy can be messy. It’s not perfect. But random affinities will give you a whole different way to access your audience and keep your content fresh. There are three keys takeaways to making random affinities work:

1. Don’t make this your whole strategy. At most, random affinities can drive 20% of your editorial calendar. You need a few directly-related topics, too.
2. Set expectations. It’s a lot easier to sustain your effort if no one expects a miracle. Make sure everyone knows this isn’t a miracle marketing solution (like those exist). But also make sure they know that, in the budget spectrum, this stuff’s low-cost and low-risk. Worst case scenario is that no one reads it.
3. Above all: If you’re still using scripts to spam links on 10,000 blogs or ensuring that your keyword is 3.5% of every page on your site, random affinities are not for you. This is the stuff that blurs the lines between SEO and marketing. Which is why I like it so much. And why it works so damned well.