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Felix Dennis says you'll never get rich working for somebody else. Not rich-rich like he is, to the point where he can only estimate that he's worth somewhere in the hundreds of millions of dollars.

Dennis is the chairman and founder of Dennis Publishing, a privately owned London company that publishes dozens of magazines, including The Week, and which sold Maxim, Blender and Stuff to a private-equity firm in 2007 for about $240 million.

His journey as an entrepreneur began shortly after he was briefly imprisoned in England in 1971 for editing a humor magazine that the government deemed obscene. Upon his release, determined not to become "the token hippie in some record company," Dennis began pestering acquaintances for capital and publishing small magazines such as Cozmic Comics and Kung Fu Monthly, patching together financing and good will from friends, printers and distributors.

His book "How to Get Rich: One of the World's Greatest Entrepreneurs Shares His Secrets" mostly skips the braggadocio and platitudes typical of self-made-millionaire memoirs. There's entertaining and practical advice for early-stage and growing businesses about raising capital, hiring talent and negotiating, with particular focus on the necessity of maintaining ownership -- the key to eventual riches. There's a lot about his mistakes, too, including an admission that in the late 1980s and early 1990s, Dennis blew through $100 million "on drinking, taking drugs and running around with (prostitutes)" before landing in a hospital.

Driven by desire

A published poet, Dennis wrote the book without a ghostwriter. He spoke with Inc.com from his New York office.

For a book called "How to Get Rich," you spend a lot of time dissuading potential entrepreneurs from trying. You say I'll need to get used to groveling and failing, and I'll need to be so driven, that it may put my marriage at risk or hurt my relationships with my kids.

It's kind of a crazy thing to decide that you're going to be worth tens and tens and tens of millions of dollars and set out to do that. It doesn't suit everybody. I warn people throughout the book that if you're not driven by this desire, you really shouldn't try. It will lead to a lot of heartache and a lot of sacrifice, and not just you doing the sacrificing.

OK, so say I'm ready. I have a great idea. Now what?

I think having a great idea is vastly overrated. I know it sounds kind of crazy and counterintuitive. I don't think it matters what the idea is almost. You need great execution. A lot of people say they've got this great idea, and "if only I had the capital" they'd go out and do it. Usually this is a fantasy. It's just an excuse for not confronting their fear of failing.

How does fear of failure come into it?

You're bound to fail sometimes. It's a 100% certainty. You've just got to ignore the fact that some people will laugh at you. It makes them feel better that they haven't even tried.

But a great idea can't hurt, can it?

As long as you do not become more interested in proving to others that your idea was right. I made this mistake with Blender, which in its original form was a magazine on CD-ROM. It wouldn't sell, but I became seduced by the technology instead of listening to what the numbers were telling me and what wiser heads in business were telling me.

I was just so in love with the idea -- and proving that I'd been right to back it -- that I kept pouring good money after bad. I wasted 4, 5, 6 million bucks.