Before I was a writer, I worked in politics, for one of the country's most independent and unconventional politicians -- Jesse Ventura. He often prided himself on not reacting to pollsters, instead following his gut. That instinct served him reasonably well.

I tend to share the former Minnesota governor's disdain for polling. I was reluctant to even buy Mark Penn's and E. Kinney Zalesne's Microtrends: The Small Forces Behind Tomorrow's Big Changes. Truthfully, I couldn't fathom how political pollster Penn could teach me anything remotely useful to an investor.

But I was wrong. The book holds a surprising number of microtrends, and in many cases, it doesn't take a reader much effort to spot potentially profitable opportunities.

Change -- the only constant
"Even when trends are staring us in the face, we often don't see them," Penn writes. I have several single, female friends who have purchased homes recently. It never occurred to me that, as a group, they might be the second-largest segment of homebuyers in the U.S. After reading Microtrends, I now know better. The in-store campaign Home Depot (NYSE:HD) has initiated, aimed directly at better serving this burgeoning demographic, suddenly made sense to me.

The book also makes a compelling case that companies such as Wal-Mart and Target (NYSE:TGT) should begin directing advertising campaigns at stay-at-home dads. I have a number of male friends who are now the primary caregivers for their families. They do most of the shopping; it only makes sense that more retailers pursue this strategy.

To date, though, I haven't seen much of a shift in strategy by major retailers. If I do, however, it is possible that I might make an investment based on the company's willingness to exploit this microtrend.

Another wonderful example that might have escaped most people's attention is the fact that the average video game player is age 33. If you had asked me before I read the book, I would have guessed 17 or 18. But 33? The opportunity for investors here is to gauge how much companies such as Microsoft and Sony (NYSE:SNE) are able to mimic the success that Nintendo (OTC BB: NTDOY.PK) has had in marketing Wii to the post-pubescent crowd.

Watch what I do, not what I say
It may not be obvious, but people have extremely long commutes, they pamper their pets, they dislike the sun. And young people do not broadcast their knitting skills. Nevertheless, each of those elements is a microtrend, and investors would be wise to understand these and other subtle changes  pulsing through society.

For example, did you know that Starbucks (NASDAQ:SBUX) opens some shops as early as 5 am to profit from extreme commuters -- people who drive more than 90 minutes each way to work every day? Or that Honda (NYSE:HMC) has developed a car called the Wow, designed for people who are passionate about transporting their pets safely?

For sun haters, some companies are developing clothes with sun-blocking capabilities. Other companies, such as Nike (NYSE:NKE), sell do-it-yourself shoes that young knitters can fashion together in their own style.

Foolish last word
The book identifies 75 microtrends, and while not all lend themselves to investing insights, many do. Willing investors can beat others to the punch to find companies poised to exploit the microtrends.

Interested in other Foolish reviews by this writer? Check out these articles:

Home Depot, Wal-Mart, and Microsoft are Motley Fool Inside Value recommendations. Starbucks and Nintendo were both chosen in Stock Advisor.

Fool contributor Jack Uldrich is the author of The Next Big Thing Is Really Small: How Nanotechnology Will Change the Future of Your Business and the forthcoming book Jump the Curve: 50 Strategies for Dealing with Emerging Technologies. He owns stock in Microsoft. The Fool has a strict disclosure policy.