Engaging with both new and returning customers is crucial to growing your customer base. These four marketing tactics will help you build lasting relationships.

1. Loyalty programs: Loyalty programs reward customers for repeat business with discounts, rewards points or special events. They can be as simple as a paper punch card or as high-tech as a plastic card tied to a computer database. Make sure your loyalty rewards reflect your business’s brand and motivate your target customer. Capture customer data including emails, addresses and phone numbers as part of your loyalty program. You can also use geolocation websites to offer loyalty rewards.

2.  Socially responsible marketing: Aligning your business with a social cause can increase loyalty by convincing customers you care about the same issues they do. Choose a cause that is relevant both to your business and to your customers. Can’t decide on a cause? Ask your customers for suggestions. Remember, it doesn’t have to be a big, global movement—in fact, if your business relies on local clients, supporting small community organizations can be more effective.

Research the organization to make sure it’s legitimate. Then decide how you will support it—whether by collecting donations from customers, hosting a fund-raiser, volunteering or donating a percentage of your sales. Publicize your relationship with the cause in your online and offline marketing materials, and tell local media about your charitable activities.

3.  Customer service: Customer service can make or break a small business. Regularly examine your business with an impartial eye, or recruit a friend or relative to do it for you. Start outside and pretend you’re a new customer: Is your business easy to find, with adequate parking? Is the parking lot well lit? Does it look welcoming, clean and appealing? How are customers greeted? Call your business and see what kind of response you get. Is the phone answered quickly or does it ring and ring?

Today, customer service starts online, so don’t forget to check out your website. Do the links work? Are coupons or special offers current? Is your contact information (phone and email address) up to date?

4.  Apps: Creating a smartphone application (app) for your business is the latest way to stay in touch with customers. Apps enable you to “push” information out to customers who signal they want to hear from you by downloading your app. Apps also help you reach the crucial audience of consumers who use mobile devices to find the products or services they need. There are many companies that provide custom apps for small businesses in specific industries.

To learn more about Groupon’s merchant solutions and how to work with Groupon, visit www.GrouponWorks.com.