It’s not always easy to hear criticism, but for pizzeria owners, it can be critical to your business. From comment cards to secret shops, different feedback methods will get different results. Here’s what you need to know about four common kinds of customer feedback and how you can best use them to help boost your bottom line.

First, let’s take a look at comment cards. Getting quality responses is the biggest goal. It may be one of the oldest methods of getting customer feedback, but there’s a reason you still see comment cards at most every casual dining restaurant around: they are one of the best meters for gauging customer feedback.

While it can seem like negative voices are the loudest (they can stick out in your mind the most, as well), comment cards allow owners to keep things in perspective by offering a more balanced look at how people respond to your restaurant, says Anthony Russo, CEO and founder of Russo’s New York Pizzeria, based in Houston, Texas. “The comment cards are really what count the most to me,” Russo says. “When people are there, in the restaurant, filling it out, and they’re saying ‘hey, this was a good pizza or a good pasta dish,’ we know we’re doing a good job.”

On the other hand, if they have criticisms, he knows they’re in the restaurant at the time they’re writing these things, and that they’re something the staff and management really need to address. “We have meetings where we sit around and read the comment cards,” he says. “This is really important feedback for us.”

Another feedback method more restaurants are moving toward is the online survey. Often found on receipts, online surveys usually offer customers a chance to offer feedback on their experience in exchange for some sort of incentive, like free meals or other giveaways.

Online surveys can be a good way for pizzerias that heavily focus on delivery to get direct feedback from customers. It can also be a boon for restaurants that want to increase their customers’ online engagement with their brand, says Cody Pierce, VP of Marketing at Pizza Ranch, which is based in Orange City, Iowa.

Pierce says to move customers from just hearing about the survey to actually giving their feedback online, Pizza Ranch offers everything from gift cards to larger incentives like trip giveaways. And they let their customers know. “The survey information appears on all the receipts, and we have the managers walk around the tables and talk about the survey and the incentives,” he says.

And it actually does matter what you offer customers in return for their time to take the survey, Pierce adds. “The number of surveys actually does change when we have just a weekly gift card giveaway versus a larger trip giveaway,” he says.

It may not get the largest sample size for feedback, but manager interactions can make a huge difference in building brand loyalty among customers, and it can help managers get a better idea of what’s going on at the table-level.

“I grew up in my parent’s restaurant and I used to watch my dad walk around to all the tables and talk to the customers,” Russo says. “That way, you find out if something is wrong right away and you can fix it then and there.” Russo says the restaurant also calls back customers who make large delivery orders and checks with them to make sure they were satisfied. “It’s a personal touch, and it makes a difference,” Russo says.

Secret shoppers can be another tool in an owner’s customer feedback arsenal. While a regular customer may come to a restaurant and just feel like it was “slow” or “not really that nice,” a secret shopper can give owners information about specific operational details.

Timing on orders, cleanliness in different areas of the restaurant, interaction with waitstaff and even the volume of ambient music are all things secret shoppers can offer feedback on. “If we ask our guests about their overall satisfaction, these are all things that would factor into that,” Pierce says. “But they wouldn’t be focusing on all those in detail. The secret shops can give us those details so we’ll know what we need to improve for the overall guest experience.”

Alyson McNutt English is an award-winning freelance writer specializing in home, health, family, and green topics. She is based in Huntstville, Alabama.