I like to think I know quite a bit about marketing.

I study extensively and I have nearly two decades of experience.

Yet I'm often wrong about lots of stuff.

I'm always surprised by the answer to at least one question when I run surveys. And when I've been running my recent pay-per-click advertising campaigns I've consistently guessed wrongly about which ad and which landing page will be the most successful.

My saving grace, I guess, is that I'm more interested in the truth than in proving myself right. So I'll run surveys. I'll test two different ads and pages to see which wins.

So even if my instincts let me down, the numbers tell me the right route to go down.

I see lots of people falling foul of this and relying too much on their instincts.

Because they don't like an email or an advert or a presentation, they assume no one will.

Because a web page appeals to their sense of aesthetics, they assume it will work for their business.

They're wrong again and again. But what can save them is testing.

Testing shows you what really works. And in doing so it improves your instincts for next time.

Google have a testing tool called “Content Experiments” as part of the free Google Analytics account. And for a small fee, you can get “what you see is what you get” testing from Visual Website Optimizer or Optimizely.

It can all sound a bit geeky to be honest. Not at all the big thinking and grand strategies you'd expect marketing to focus on.

But I've run plenty of tests where one variation has outperformed the other by 40% or more. So that small amount of time spent thinking about what to test and creating the test in the tool has had huge results.

How would your business change if you got 40% more web traffic? Or 40% more email subscribers. Or 25% more people clicking the buy button.

All possible without any massive strategy changes. Just regular testing and tweaking.