For someone starting a business, it’s possible to do it alone, but it’s easier with help. There are limits to what you know, limits to how much you can get done, and limits to where it’s valuable to spend your time.
Tech companies typically start with someone who knows how to make the product (i.e., Wozniak) and someone who knows how to sell it (i.e., Jobs).
In traditional publishing, the co-founder is similar to the agent or acquiring editor. You, the author, create the product, the others know how to sell it. They’re more than just a hired sales force because they sign on to the potential of what your book can be, and they succeed or fail based on your ability to bring it off together as a finished product.
In indie publishing, you’re out there alone. You don’t have someone to do the half of the work that you don’t want to do. You’re the creative department, the engineer, the suit, the artist, and the capitalist pig. You can (and probably should) hire some of that work out, but an employee is not a co-founder. You can always proceed without his say so, decide the book’s ready, or decide he’s full of it and hire a different editor, or artist, or, formatter.
Founders, as a team, are 100% responsible for success. When you have a co-founder, you share that load. Jobs and Wozniak got to share. Mark Zuckerberg didn’t. He may not have built Facebook by himself, but in a sense he did it alone, because he was the only one success depended on.
Independent success is challenging because it requires you to execute on your weaknesses as often as your strengths. You need to do the part of the job you love, and you need to do it very well. But you also need to be ruthless about requiring yourself to do the part of the job you hate. No one else will do it for you.