Cramer boiled it down to three reasons: first, its specific operation niche; second, its compelling drive-in concept; and third, its promotions.
Sonic has some 3,500 drive-in style restaurants across the United States, and, unlike many other fast casual chains, it operates in a very specific niche. In an environment that is increasingly health conscious, Sonic is synonymous with indulgence.
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The company has worked to create a quality menu with offerings at affordable prices that appeal to value conscious consumers, even if it isn't healthy.
Sonic has also been very smart and selective about the way it uses promotions. In its most recent conference call, CEO Cliff Hudson talked about the need for a more long-term approach to its promotional strategy, rather than offering quick short-term deals to drive traffic. So, instead of cutting prices, he is focused on the customer's perception of value.
"Put it all together and you've got a brand that can go toe-to-toe with Steve Easterbrook's McDonald's, which is why I think Sonic is still worth owning," Cramer said.
When Cramer considered the company's long-term growth rate of nearly 18 percent, the price-to-earnings multiple of 22 actually seemed inexpensive.
"This is a well-run company, and I bet its stock continues to run," Cramer said.