First, and please forgive us, but: Must you?

Consider the challenges of a straightforward business partnership. Then consider the challenges of a marriage. Then consider the multiplied difficulties when combining them.

This sounds to you like a plan?

Though there are no accurate statistics about what happens when spouses try to run a business together, expert estimates are grim: "Only 5% of couples can make all-in partnership work," says Azriela Jaffe, a frequent reporter on the phenomenon of entrepreneurial couples and author of Permission to Prosper: What Working Wives Crave From Their Husbands, and How to Get It. ("All-in" co-ownership is tougher than a partnership in which one spouse is a subordinate who's helping out.)

Still, we know you'll try it anyway. And there is, potentially, an upside, says Kathy Marshack, a widely known business coach and psychologist who specializes in working with entrepreneurial couples (and who has written Entrepreneurial Couples: Making It Work at Work and at Home). "There's potential for tremendous personal growth," she says. "When you're confronted constantly by someone who knows you so well, you're going to have an extraordinary opportunity to work on your flaws and develop as a person."

"When it does work," Jaffe agrees, "it can be glorious."

These days, co-CEOs Michele and Steve Ferree agree. But it's taken some doing -- or, rather, is taking. "There's no finish line; it's an ongoing process," says Steve. The two longtime McDonald's executives decided even before they married to buy and build a Mr. Rooter Plumbing franchise in Portland, Oreg. They took the plunge as entrepreneurial spouses in 1999 and now have a 27-employee company with $3 million in sales. They've learned some things. And they, together with experts, observers, and other (sometimes failed) entrepreneurial spouses, have some advice.

Plan no-business weekends. Go on actual dates. Make rules.
  1. Don't do it by accident. Go into business with your spouse only if the two of you have mutually planned it, says Jaffe, "not because other options have failed."
  2. Acknowledge competitiveness. Recognize that in a business you're always competing, even with your spouse.
  3. Be prepared for business to get personal. "Talking to a business partner who's also your spouse is different," says Steve Ferree. "You take stuff more personally -- and your spouse is more honest with you." "Which can be good and bad," Michele Ferree adds.
  4. Don't get stuck in typical gender roles. At the office and at home, start with a clean sheet of paper.
  5. Establish a real separation between work and home. Schedule quarterly long weekends with zero business. Take occasional separate vacations. Go on actual dates with no business talk involved. Make rules.
  6. Fight the business's unfair pull. Every entrepreneurial couple claims the relationship is their first priority -- but then the phone rings. Learn not to answer it.
  7. Get a counselor or a coach. And it must be one who can sort through the business and the marriage simultaneously. A bonus: The simple act of deciding to use one is a powerful reminder of the marriage's priority.
  8. Keep asking the right questions. Am I being true to myself? Am I helping my partner be true to himself or herself?

The payoff, for those who can make entrepreneurial coupling work? "We've discovered," says Steve Ferree, "that the business is just a vehicle to bigger things. For me, it's about being a better husband, a better father, a better employer."

A better person. That, bad odds be damned, would be the glorious part.