With the fast-selling e-publication of his memoir-cum-business-strategy guide, Mark Cuban made another notch in his media-pioneer belt.

In one day, the slim under-100-page book, titled How to Win at the Sport of Business: If I Can Do It, You Can Do It, soared to the top of the bestseller charts at the big online book-buying sites, with particularly strong sales on Amazon, iTunes and Barnes & Noble.

We caught up with the defending NBA-champion franchise owner and media-business entrepreneur as he was, in characteristic fashion, running his own promotional campaign for the book.

Q: Were you surprised at the immediate great sales?

A: I had no idea what to expect. I literally didn't ask anyone what a good number would be. So when it popped up on the bestseller lists and at the top of all business books, I was truly surprised. This is new to me. This is new to the industry. From here, hopefully I will be able to figure out whether this is just a one-off situation, or something that I or others can replicate. Maybe I just got lucky.

Q: Of all your business ventures, the profit margin for this book is unmatched. Much of the book already had appeared as blog posts, and the production, promotion and distribution costs were negligible.

A: Yes. That is what made this approach so appealing. I didn't have to spend a ton of time writing and editing, and Scott Waxman at Diversion Books was very accommodating in allowing me to make edits, literally up to hours before the book was released. More importantly, I didn't have to commit to doing a book tour and a rigorous interview schedule because I controlled all the economics. I try to always be a good business partner. If a publisher had made a big investment in me, I would have felt immensely obligated to make sure they made money. Instead, I can work to my schedule and work almost exclusively from my phone and laptop to do all the promotional work.

Q: You mentioned in a blog post that after reaching millionaire status, many impresarios reach a plateau, adding that some of us want more. When did you begin to feel, as you say in your book, that family should come first and you could cut back your work week?

A: Financially, I was more in protection mode than accumulation mode after my hedge of Yahoo stock worked back around 2002. Personally, once my kids were born, that changed everything. Now with three kids, aged 2 to 8, they run my life. I think I would have imploded had I tried to balance a family and my financial goals when I was younger.

Q: Your parents wondered if you would ever be stable. Was there a point when they realized you were governing your own life quite capably?

A: I think it was when I was 16 (laughs). I was working on more business deals than school work and doing things that my folks really didn't understand. After one failed shot at trying to get me to learn a trade, which in my case was laying carpet, they realized that I was either going to succeed or fail based on my own efforts.

Q: How much of your day is spent running HDNet?

A: Most of my time is spent on HDNet and HDNet Movies. The Mavs, Magnolia, Landmark, Filesanywhere.com and the rest have great people running them, so I let them do their thing.

For HDNet, our biggest challenge is that we are an independent network. We don't have the leverage that the big media companies have. Viacom can force a distributor to take networks that no one watches as a package deal to get MTV. I mean, who watches VH1 Soul or VH1 Classic? Fox can force a distributor to take Fuel. Despite the fact that we get bigger numbers, we face a battle with every distributor because it's just HDNet and HDNet Movies.

Q: You're fighting for a piece of a pie at a time when the major suppliers of content are upping their asking price. Will the carriers have enough left to pay you?

A: Combine that with all the money that distributors are now having to pay for retrans fees, and there is a real problem for independent networks like HDNet. Fortunately, some distributors like Comcast, Verizon, Dish, DirecTV, AT&T, Charter and others realize that and are working with us. Others won't. I feel like we are carrying a torch for independent networks. We are quickly becoming an endangered species, which would be a huge shame. I think the last thing consumers want is all of their TV content being determined by five or six major media companies.

Q: You've indicated before that you fear the media marketplace could become monopolistic.

A: It's a topic we are aggressively pursuing with the FCC. As much as I hate dealing with business issues via D.C., I think it's a battle worth aggressively fighting.