Do you realize how much the market values your attention span? Billions of dollars are spent each year by companies to reach your eyes, your ears, and (ultimately) your mind.

Why do they want your attention so badly? Thoughts result in decisions, behaviors and habits. If an advertiser can get access to your mind, he can influence you and more importantly, your purchases.

This is not a diatribe against evil advertisers, a material world, technology overload, or even noise pollution. But the truth is, to stay effective you need to stay focused. And if you valued your own attention span as much as others do, I think you would be a bit more vigilant as to what you let in.

So my question is simpler: How are you controlling the access to your mind? Is it intentional, thoughtful, beneficial? If you're not in control, consider using these tricks to determine when and how to unplug.

1. Own your attention span.

Forget billboards, radios, TV and print advertising for a moment. These types of advertising are decades or more old and you have developed some filters to help control your responses. The more insidious attention vampires are on your smartphones, tablets and computer screens.

Every app, game, search engine and access point is now an attention-span off-ramp. Your productivity is dependent upon your ability to control and then actively select what gets your attention. Multi-thinking is a myth: You can't give complete and equal cognitive attention to multiple thoughts simultaneously.

So take a "one thought at a time" approach to your life. Do your email separately from your phone calls and meetings. And whenever possible, turn off the digital devices and distractions when you are engaged in cognitive work.

2. Guard your fortress.

Think of your mind as a bank–the place you store such valuable items as thoughts, dreams, skills and experience. So naturally, you need to protect it. Don't leave your instant messaging on while you are completing a report, participating in a meeting or formulating a strategy. It's OK to shut down your phone during times of high productivity that require your full attention.

3. When you break, break hard.

OK, digital addict: Now that you've taken back control from the attention vampires, you can live a life of full control and focus. But what about all of the fun? The ESPN scores, the Facebook status updates, the Words with Friends games?

I don't want to send you to a mental monastery. Rather, take breaks for digital escapes–but break hard. Apply the same level of focus to your : Close your email, stop your projects, shut your door and open your favorite Zynga game. You have earned it, so revel.

Then get back to work.