America's fourth largest burger chain has made a habit out of advertising in areas they don't actually have restaurant—for good reasons.

From its roots in Oklahoma in the 1950s, Sonic Drive-In has slowly grown into America's fourth largest burger chain and 12th largest restaurant chain overall with 3,578 locations in 45 states. But though by now you've almost certainly heard of Sonic, in many regions of the country, you may remember being surprised by how you heard of it—not from seeing a new location in your area, or even from word of mouth, but instead through one of the chain's television ads despite the fact that there weren't any Sonics in your area.

If you've ever experienced this strange Sonic phenomenon, rest assured that you're not alone. Plenty of people can attest to seeing Sonic ads despite living nowhere near one of the fast food drive-ins, and turns out, that somewhat frustrating marketing plan was created by design. In a discussion with Business Insider, Sonic CEO Cliff Hudson described this tactic as creating "national awareness with a super-regional footprint." Hudson admits the decision has an economic benefit to his company. "It's cheaper and more efficient, because we do business in 45 out of 50 states, to buy nationally," he explained. "You get the airtime cheaper and you get better placement." But advertising this way works in a more underhanded manner as well, building interest in areas before the brand has even arrived. Hudson said that, in the past, one of the biggest challenges when entering a new region was raising brand awareness; now, it's not uncommon for a new Sonic location to see customers lining up as soon as it opens its doors.

The idea that people want what they can't have is one of the oldest psychological tricks in the book: It's actually a bit surprising more advertisers don't try this strategy. That said, as a chain, Sonic is in that sweet spot of national presence and continued growth where advertising nationally—even where you don't currently have locations—is economically viable. Plus, there's probably a larger moral here too: If you don't have a Sonic Drive-In nearby, you'll probably get one pretty soon.