"Doing lunch" can open partnerships, close deals and offer an alternative to all sorts of formal business meetings. But many successful entrepreneurs use it to assess much more than how you order your Cobb salad.

When asked recently to share their favorite lunch locales, several entrepreneurs offered advice beyond just restaurant recommendations. They had those, too--but many of the speakers at Inc.'s recent GrowCo conference in Nashville also revealed their other rules of business lunches.

Dallas Mavericks' owner Mark Cuban, for example, avoids lunch meetings altogether, while Brittany Hodak and Kim Kaupe, the founders of entertainment startup Zinepak, choose venues as a sort of personality test for potential business partners. For Inc. 30 under 30 alum Jordan Goldman, founder of college-review site Unigo, setting a lunch meeting is also a chance to test out one of the many apps he keeps on his phone.

Here are the answers from our little questionnaire: 

Mark Cuban, owner of the Dallas Mavericks and investor on ABC's Shark Tank: "I'm not big on 'Let's go eat lunch' meetings. The only way you're going to get me for a meeting is if you're writing me a check. Same with phone calls--they're a waste of time."

Julia Hartz, co-founder and president, Eventbrite. "My favorite food spot for a business meeting is The Cavalier in San Francisco."

Brittany Hodak, co-founder, Zinepak: "One of my favorite things to do when we’re setting the meeting is to invite somebody to a quick-serve restaurant. We have a policy at Zinepak where we only work with good people, and we fire a lot of clients for being difficult or horrible or impossible. If you invite somebody to meet you at a Chili's, for instance, and they say, 'Absolutely not, I would never go to a Chili's,' it's an easy way to say, 'You know what, this is probably going to be a very difficult person to work with.'

"You would be surprised how many people would say, 'I'm not going to meet you for lunch at a Chipotle, that’s a terrible idea!' And it's kind of a really great way to gauge how much they actually care about being creative and innovative, and how much they care about their own status and how senior they are." 

Jordan Goldman, founder, Unigo: "It depends on what the meeting’s trying to accomplish. There's an app, Hoppit, that lets you search through restaurants by decor or vibe. [Pulls out his phone to show the many folders and subfolders he uses to organize his apps.] So what am I trying to accomplish, and what are the nearby restaurants? Proximity's a factor, and then you can set a certain tone. … I buy an app every morning--I test it out throughout the course of the day. A lot of them don't make it through 24 hours."

Naveen Jain, co-founder, Immunity Project: "Oliveto in Oakland, California." 

Kim Kaupe, co-founder, Zinepak: "One of the Manhattan parks. I just had a meeting the other day in Bryant Park--they have a little coffee shop/restaurant there. Obviously, six months out of the year, New York's pretty impossible to be outside, so the other six months that we do have sunshine, getting outside and meeting people is a nice way to start a meeting off."