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American companies with the most customers

Last week, Apple announced that it sold 35.1 million iPhones worldwide in the latest quarter. The figure is large, but not extraordinary. Some consumer products and consumer electronics companies sell their products to a considerably larger number of customers -- in the U.S. alone. 24/7 Wall St. examined the corporations operating in the largest U.S. consumer-based industries to find the largest companies based on customer count.

The customer bases of many of these companies are in the tens of millions. Each company operates in an industry that provides a product or a service to an extremely wide spectrum of American consumers. The leader in each sector reached its position through innovation, longevity or some combination of the two.

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Each of the industries on this list serves a very large base of customers. For example, there are thousands of retailers, serving pretty much the entire population, but only Costco is the leader in membership with over 65 million members. Founded in 1983, Costco is a relatively new company. It became a success largely because it charges customers a membership fee for access to its stores and in exchange offers extremely low prices that are never marked up more than 15 percent above the price Costco pays.

Some industries are huge, but only have a small number of competitors. There are more than 330 million wireless subscriptions in the U.S. -- more than the population itself. But there are only four competitors of any size -- AT&T, Verizon Wireless, Sprint-Nextel and T-Mobile. Each company has to battle for a share of a market that is no longer growing. The weapons the companies use to gain market share are products, customer service and price. AT&T is the leader. Its share of the market is based to some extent on history. It is a descendant from the original AT&T phone monopoly. But without strong products and intelligent pricing there is no assurance it can stay ahead of number two competitor Verizon Wireless.

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24/7 Wall St. examined 10 of America’s largest consumer industries and the customer counts for the biggest two or three companies in each sector. We then reviewed the history of each industry in an attempt to find how the top company in each reached its leadership position. To rank the companies, 24/7 Wall St. took each leader and compared it in size to the leaders in the other industries chosen. We used company and industry data to confirm customer counts. Each company in this ranking is the largest company in its industry, based on customer count.

These are the American Companies with the Most Customers.

1. Visa

  • Customers: 302 million
  • Industry: Credit cards
  • Parent company: Visa Inc. 
  • Major competitors: MasterCard, Discover

Visa, MasterCard and American Express have been in the business longer than most of the other smaller competitors. This has allowed the three companies to remain dominant for most of the last several decades. As of 2010, Visa had nearly half of the nation’s market share, at 49.6 percent. The next-largest competitor, MasterCard, had a 33.4 percent share. While American Express, which had just an 8 percent share, must rely on its own marketing to distribute membership, Visa can use banks as issuers, making it much easier to gain the kind of market share it has.

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2. iTunes

  • Customers: 225 million
  • Industry: e-commerce
  • Parent company: Apple Inc.
  • Major competitors:, eBay, PayPal

There are at least 225 million registered Apple iTunes accounts worldwide. These are accounts that are tied to a credit card. After reaching the 200 million mark in March 2011, the now-late Steve Jobs stated that “Amazon doesn’t publish their numbers. But it’s very likely that this is the most accounts with cards anywhere on the Internet.” Apple’s iTunes Store, which originally sold only media content, has benefited greatly from the addition of the Apple App Store. On March 5, 2012, Apple announced that customers downloaded 25 billion apps.

3. Delta

  • Customers: 111.1 million
  • Industry: airline
  • Parent company: Delta Air Lines
  • Major competitors: Southwest, American

Few industries have been as troubled as the big airlines in the U.S. At some point in their history, more or less every major carrier has gone through bankruptcy at least once. Delta’s merger with Northwest Airlines in 2008 made it the largest carrier in the world. As of 2010, the company reported 110.9 million annual enplaned passengers. The next largest company, Southwest, had 106 million passengers. The merger between Continental and United, approved at the end of last year, may cause Delta to lose its number one spot in the coming months.

Read the rest of the American companies with the most customers at the 24/7 Wall St. site.