You have everything set in place to run a successful restaurant, and you think your customers are happy—but you wonder whether they are truly having a satisfactory experience in your restaurant.

Is your food up to par? Is the ambience what they are looking for? Are you delivering orders in a timely fashion?

How can you tell whether you need to make any changes to ensure satisfaction? One of the best ways is by gathering customer feedback. It’s an absolute must to help you determine whether your customers are truly happy with your products and services—or if you need to make changes. You are in business to benefit your customers and make them happy. If you don’t have satisfied customers, your business can suffer immensely. In short: Customer feedback is invaluable.

So, how do you go about gathering customer feedback that can actually help you properly gauge how your restaurant is doing? Here are some simple ways to gather useful insight.

1. Distribute feedback cards. Feedback cards are a great way to gather customer thoughts on your restaurant. Have your wait staff drop these cards off when they deliver the check and ask them to encourage customers to fill them out.

You can set the cards on the table next to the napkin holder, but making it part of the process to have servers ask for feedback will increase the number of responses you get. Have the servers bring back the bill and ask politely. Most people will be happy to leave feedback once they know it will be used to improve their future experiences.

These cards can feature specific questions related to elements of your restaurant that you are curious about and you can ask customers to either provide specific answers, or to rate their satisfaction on a scale of 1-10 or 1-5.

2. Create a comment form on your website. Incorporate a satisfaction form on your website and ask your customers to fill it out. You can point their attention to this form by highlighting it on their check.

We’ll talk about email in the next point, but you can also use social media to get feedback. Direct your social media followers to the form on your website. Make the survey easy to use and express how the feedback is used to improve the restaurant. For example, give an example on social media of a customer request or feedback item. And show how you’ve used that. It might have been a suggestion to add a new menu item or make more room between tables.

People will act if they know you’re listening.

3. Do an e-mail survey. Send your mailing list a survey via email. Include questions on the survey that will help you gauge satisfaction.

If you don’t have a mailing list, you really need to start one, as it can help you in others ways: promote new menu items, let your customers know about special promotions or events and so on. Keep engaged with them by sharing events you’re hosting or even by sharing events in your restaurant’s area.

Provide value in as many ways as you can to make your newsletter appealing. Then you can survey the subscribers every couple months to get feedback on various aspects of your restaurant.

Another strategy is to ask for feedback on recent things you’ve done. Ask people about new menu items. Ask if they like the décor change you recently made. You can get feedback that will be actionable for you so you can continue making improvements.

4. Analyze your numbers. Your customers are always giving you useful feedback even when you’re not asking for it—it’s all in the numbers.

Which items are you selling the most of? Which are you selling the least of? You can easily see which items are being ordered the most, especially if you are offer an online ordering system.

Using these methods, you will be able to see what your customers are doing and not just what they tell you. This allows you to gain a better idea of how satisfied your customers are.

Many restaurants offer discounts to gather information from customers. If you’re comfortable giving away a coupon or some sort of offer or incentive you can probably increase the number of responses.

But make sure you’re not undermining your brand reputation. It’s always good to incentivize customers through other ways, such as making them feel like their feedback can really lead to change in the restaurant.

Brian Casel is the founder of Restaurant Engine, a website design solution for restaurants. Contact Casel for more suggestions on soliciting customer feedback.