By Trey Thoelcke and Michael Sauter

The most profitable retail stores in America? It may surprise you, but they belong to Apple (AAPL).

According to RetailSails, a retail and consumer goods consulting firm, the tech giant’s 372 worldwide locations sold goods at a rate of more than $6,000 per square foot of floor space in the past 12 months. The average store of the next most successful company in the United States, Tiffany & Co. (TIFF), sold less than half that figure per square foot.

The retailers with the most profitable stores all brought in more than $1,000 per square foot. They were mostly high-end brands, selling relatively expensive products. Among department stores and supermarkets,  sales per square foot were in many cases less than $100.

Based on the RetailSails report, 24/7 Wall St. identified the most successful retail stores in America. The top 5 are listed below.

The difference? In most department stores and discount stores like Wal-Mart (WMT), Kmart and Family Dollar Stores (FDO), most items cost less than $100, and most stores are very large. The average retail space in some of the least successful stores by sales per square foot is at least 10,000 square feet. This prevents the total profits per square foot from exceeding several hundred dollars, even at the most popular stores.

At the most profitable corporate stores, the opposite is true. They sell luxury goods, in apparel, accessories, electronics or jewelry. Their products are often quite expensive, while the stores are generally relatively small. The average store floor space of most of these companies is less than 5,000 square feet.

While total sales of the average Kmart store is roughly double what Lululemon Athletica (LULU) stores do, the average floor space of a Lululemon is only 1/34th that of a Kmart store.

Relying on RetailSails’ 2012 Chain Store Productivity Guide, 24/7 Wall St. identified the nine companies with the highest sales per square foot, based on the past 12 months of sales. Retailsails also provided average store size, average annual sales per store, one-year sales growth and the number of stores.

Below are America's 5 most profitable stores; for the full list, visit 24/7 Wall St.

• 1. Apple (AAPL)
   Sales per sq. ft.: $6,050
  Sales per store: $51.14 million
  No. of stores: 372
  1-yr. sales growth: 28.9%
  Revenue: $156.5 billion

Apple is a relative newcomer on the retail scene, with its first store opening in 2001. Yet, Apple’s $6,050 per square foot is more than double that of Tiffany’s, the next highest on the list. Apple also has the ninth highest sales per store among companies measured by RetailSails, at more than $51 million, and the 13th highest one-year sales growth, at 28.9%. Apple benefits from constant new product introductions and upgrades of existing ones, as well the fact that so much of its revenue comes from non-store sales. This business model has made Apple the world’s largest public company, with a market capitalization of more than $510 billion. In the first nine months of fiscal 2012, Apple opened 15 stores, including four in the United States, four in Spain and two in France.

• 2. Tiffany & Co. (TIFF) 
  Sales per sq. ft.: $3,017
  Sales per store: $13.02 million
  No. of stores: 260
  1-yr. sales growth: 9.6%
  Revenue: $3.6 billion

Diamonds are small and pricey, so it should come as no surprise that this luxury jeweler can be found near the top the list featuring sales per square feet. In fact, Tiffany’s sales per square foot is about 35% higher than that of Lululemon, the next highest on the list. Tiffany opened its first store in 1837. As of the end of July it had 260 stores. In the second half of the year, the company said it expects to open nine stores in North and South America, five stores in the Asia-Pacific region and one store in Europe. The share price is down about 7% year-to-date. 

• 3. Lululemon Athletica (LULU)
  Sales per sq. ft.: $1,936
  Sales per store: $5.49 million
  No. of stores: 189
  1-yr. sales growth: 38.6%
  Revenue: $1.0 billion

Founded in 1998, Lululemon is a yoga and sporting apparel company headquartered in Vancouver, B.C. Not only are its sales per square foot higher than all other retailers on this list except for two, but its sales per store are higher than most apparel stores as well, even though it has substantially less store space than other companies. Still, Lululemon’s one-year sales growth was the eighth highest on the RetailSails list, and its share price is up nearly 50% year-to-date. The company said it expects to open 30 new stores in the United States by the end of the fiscal year. 

• 4. Coach (COH)
   Sales per sq. ft.: $1,871
   Sales per store: $5.19 million
   No. of stores: 833
   1-yr. sales growth: 15.9%
   Revenue: $4.8 billion

Best known for its high-end leather handbags, Coach had 833 stores worldwide as of the end of July, more than any of the nine most successful retailers on this list. Its $4.76 billion revenue last year was higher than all the other retailers on the list except for Tiffany and Apple. Coach’s primary markets are the United States and Japan, which account for about 80% of all stores. It had a respectable 15.9% one-year sales growth last year, but so far in 2012, Coach’s share price has declined by more than 11%.

• 5. Michael Kors (KORS)
   Sales per sq. ft.: $1,431
   Sales per store: $3.24 million
   No. of stores: 253
   1-yr. sales growth: 77.9%
   Revenue: n/a

Luxury lifestyle products retailer Michael Kors Holdings saw the second largest revenue growth, at 77.9%, among the more than 200 companies reviewed by RetailSails. The company’s share price rose more than 110% since the initial public offering in mid-December of last year. The company believes there is long-term potential to grow its store base to 400 in North America and 100 each in Europe and Japan. The company said in its just-released second-quarter fiscal 2013 report that, including licensed locations, there were 349 Michael Kors stores worldwide at the end of September.

Visit 24/7 Wall St. for the full story on America's most profitable stores.

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