Every month, the managers of Parasole Restaurant Group's 10 restaurants meet with their bosses. At the outset, they get a report card — not for sales or profits, but an algorithm-based assessment of how their operations are faring on social media. It includes a letter grade.

"I can guarantee you," said Kip Clayton, Parasole's vice president of marketing, "you don't want to have an F."

So on top of all their other responsibilities — monitoring food prep, making sure the wine list is up to date and that there's enough Diet Coke syrup on hand — the folks at the helm of Manny's, Salut, Burger Jones and other Parasole holdings listen and react to every tweet, post and comment they get online.

Especially on Yelp, which has supplanted not only Zagat but the Yellow Pages as the go-to restaurant guide. Since it was introduced less than a decade ago, the user ratings site has grown to 102 million unique visitors per month, with about 20 percent of its traffic going to restaurant pages.

The popularity of Yelp, along with Urban Spoon, Foursquare, Open Table and others, has created a tightrope walk for restaurateurs: They can now engage with their customers 24/7, but they have very little control over the conversation. In a business that lives and dies by reputation, they have to use caution when defending themselves against regular attacks.

User favorites ranging from Minneapolis' Bar La Grassa and Tilia to St. Paul's The Nook have hundreds of Yelp reviews apiece. And while those restaurants all have earned 4.5 out of 5 stars overall, some of the critiques are soaked in the snarky salvos so prevalent on the Internet.

"I wish there was a way to say 'Let's be decent, folks,' " said Stewart Woodman, chef and owner of Heidi's in Minneapolis. "You really have to have thick skin in this business."

He's right, said Christopher Lower, social media director at Sterling Cross Communication. In fact, Lower compares Yelp to "TMZ [because] people go there for the trashy comments."

Still, he considers Yelp and other such sites "a necessary evil for restaurants," and he says the biggest challenge for restaurants is "learning how to deliver customer service online."

A matter of engagement

Many local restaurateurs have already figured out that ignoring the DIY reviews is not an option.

"Our whole philosophy on social media is that if you're a bar or restaurant, the world is talking about you day and night," said Clayton. "You can listen, or you can be stupid and ignore it — and it comes back to haunt you."

While some restaurants have hired consultants to find every mention of them on the Internet, others try to do it themselves.

Frederico Navarro, owner of George & the Dragon, said he and wife, Stacy, reach out to every Yelp commenter.

"If a guest takes the time to give us feedback, we will always take the time to send them a message back," he said via (of course) e-mail. "We try to use Yelp to connect with our guests and either thank them for coming in or let them know that their feedback is being heard and we would see what we could do to improve."

Avid Yelp user Mahesh Kothamangalam got that kind of personal response. The Roseville resident recently wrote a favorable review of a restaurant he had visited. In the review, however, he mentioned that the tea was a little cold. "And the owner actually apologized and said the next tea's on him," said Kothamangalam.

But what's happening online may have to take a back seat to what's happening in the kitchen.

Stephanie Shimp, co-owner of Blue Plate Restaurant Co., said she and her managers monitor as many sites as they can, including Yelp, Urban Spoon, Instagram and their own eClub database. She added that at Blue Plate, which owns seven restaurants including Edina Grill and Three Squares, "we balance that with what's most important … and that is who is sitting at our tables right now."

Sorting through reviews

Woodman has had his share of run-ins online, including an anti-Semitic post on Yelp that he ultimately enlisted the Anti-Defamation League to have removed. And he admits that his wife and business partner, Heidi, has "had to stop me" from responding in kind to nasty comments on Yelp. But he's devised a way to make the site work for him.

"We're kind of gleaning it, to learn how to be better, and also to build some relationships," he said.

Users, too, have to learn how best to use Yelp.

Because it's so popular, sorting through all the reviews can be daunting. That's why Annie D'Souza, the site's Twin Cities community manager, said she and other experienced Yelpers study the reviewers.

"I look at how much they've written, do they have a photo. I definitely follow a few people, some personal and others that I just trust," she said. "We're building a community of users."

D'Souza downplays the effect a negative review can have, in part because of that community.

"While business owners tend to fixate on a less-than-glowing review, consumers look at the overall rating and read a number of reviews before making a decision."

In the end, though, a pre-Internet business platitude rules: The customer is always right.

"When it comes down to engaging the guest," Clayton said, "it's better to apologize rather than get in an online argument. You're going to lose that one every time."