Costco superfan couple is on a mission to visit the retailer giant's locations in every US state

It is crucial that humans feel passionate about something. It gives people the direction they need in their life. It becomes the inspiration, which makes them get up every day and take on the world. For David and Susan Schwartz, that passion is Costco. They not only love the retailer giant's products but also the tidbits associated with them. They have translated their love for this beloved store chain in their book, "The Joy of Costco: A Treasure Hunt From A to Z." The book has been enhanced by the beautiful illustrations provided by Martin Hargreaves. At present, they are in the pursuit of visiting one Costco store in every state of the country, reports TODAY.

"In Jackson, Mississippi, it's already 100 degrees. We're going to at least one Costco in every state of the country and this is our 41st state," David told the outlet. "I think we have five more states to close on 46." Costco has over 850 locations in the world. It has stores in countries like Australia, Iceland, France, Japan, Mexico and the US.

The couple had visited many countries to gather information for their book. They went into the warehouses in each of these countries to understand how the store functions. To conduct research for their book, the couple interviewed people from all the sections of the company. They visited vendors, distribution centers and manufacturing facilities to get a feel of how everything came to be for the fifth largest retailer in the world. Though some cultural differences were visible, ultimately, there was a shared commitment to bring the best of everything to their customers.

Susan, in her interview, compares their passion to that of baseball lovers. Hardcore baseball fans visit stadiums in each state that they visit and the couple likes to do the same for Costco. Every time they visit a place, they ensure to check out the Costco store of that town, state or city. She explains her feelings by saying, "It's a treasure hunt. It's like an Aladdin's cave of joy. It's my happy place."

Talking about their recent pursuit, Susan shared, "We'll have been to a Costco in each of the 14 countries around the world and then one of each of the 46 states plus Washington, D.C. and Puerto Rico." The only places left on their list are New Hampshire, Vermont, Kentucky, Ohio and North Carolina. Their next stop is North Carolina.

Though they are close to finishing their adventure, David does not want it to end. He quips, "I think our last stop is going to be Ohio, at which point I'm going to fall down on my knees and weep." With their book, the couple wants to showcase the legacy of Costco. They want to answer the questions people might have about the store and also provide readers with facts they have never heard before. The book follows an alphabetical system. Every alphabet focuses on a specific aspect. "A" brings to readers facts about the smallest Costco store in Alaska. Z gives readers a peep into the Costco shop in Zama, Japan.

The Schwartzs are confident that after reading this book, people will have a deeper understanding of how Costco prioritizes its customers. "Costco sells 3,800 to 4,000 items at most, and an average supermarket sells 40,000 items," Susan says. "So when you walk into Costco, it's already been pre-selected and guaranteed for quality. But you just don't know what you're gonna find around any corner. We walked into a warehouse in Taiwan at one point and there was like a two-foot-high bottle of Glenmorangie whisky."

The couple also shared how this passion has helped them strengthen their marriage. "We have a number of shared passions and ones we pursue independently. Susan likes to say that we'll talk to anyone about three topics: Costco, birding and our grandchildren," David says. "So those are three topics where we share our passion and that brings us closer together."