Running a business is, in itself, a challenging endeavor. Running one with your spouse, though, adds a whole new dimension of complexity, and a new slew of additional challenges. There are, of course, advantages to partnering with the person whom you not only likely know the best, but whom you also most trust and love. At the same time, however, partnering with your significant other blurs any vestige of traditional work-life boundaries and blends business and personal roles - thereby potentially creating all sorts of complex business, emotional, and familial issues, and exacerbating any communication and relationship challenges.

In honor of Valentine's Day I decided to build on the advice for couple-entrepreneurs that I shared in Forbes last year, so I asked several successful such pairs to share two or three points of advice with readers of my column. Of course, the advice applies all year long, not just on February 14th. Not all of the nuggets of wisdom below pertain to every couple or business, but, collectively, they provide guidance for couples working together on a business or considering doing so:

From Dave Kerpen, NY Times bestselling author and founder of Likeable Local, who along with his wife, Carrie Kerpen, also built Likeable Media:

From Michelle Madhok, who along with her husband, Michael Palka, built and runs, a popular fashion and beauty website with millions of readers each month:

From Melissa Pensworth, who together with her husband, Bill, owns and runs a group of  Batteries Plus Bulbs stores, as franchisees of the nation's largest retailer of batteries and light bulbs:

From Lucky Gordon, who together with her husband, Shaun, built and runs uniforms provider, The House Label:

From Brian Wallace, who together with his wife, Judy, owns and runs infographic design agency, NowSourcing:

Happy Valentine's Day!