Imagine the scene: You sit in a McDonald's drive-through for what seems like hours. Frustrated beyond words, you take to McDonald's Facebook page to leave a complaint ... only to receive zero response.

Then, out of the blue, you finally get a reply ...

From Burger King. Who proceeds to offer you a free Whopper.

How would that make you feel?

That's just one brilliant example of Burger King Denmark's recent ad campaign, which was developed in partnership with Danish ad firm Uncle Grey.

The social media campaign targeted McDonald's customers who took to the brand's Facebook page to complain, reports Adweek:

Titled "The Whopper Reply," the tongue-in-cheek activity saw Burger King's customer service agents targeting McDonald's fans by replying to their messages with a funny answer and a link to redeem a free Whopper.

On September 24, Burger King scrolled back through more than 1,000 comments McDonald's fans in Denmark had made stretching back days, weeks, months, and, in some cases, years.

"Customer service should be fit for a king," claims the Burger King ad. "And while we're not perfect, we do our best to help everyone. Even our old friends." (You can view the full ad at the end of this video.)

"We waited two hours in McDrive!" exclaimed one commenter.

"Well, everyone can have a slow day in fast food," responded Burger King. "Here's a quick Whopper."

"We only got one bun in our Big Mac!" complained another customer.

"Big Mac convertible? How innovative," replied Burger King. "Here's a two-bun Whopper."

"Why do you call it the Big Mac when it's not?" asked yet another disappointed McDonald's patron.

"In their defense ... nobody wants a 'Small Mac,'" answered Burger King. "Here's a regular Whopper."

Daniel Schröder, marketing director at Burger King Sweden and Denmark, told Adweek that his company hadn't been doing well enough taking care of their own guests online. "When addressing this, we realized there are even more burger fans out there who deserve a reply," Schröder said. "We did what we can to help out, hoping some flame-grilled Whopper love can help make things better again."

The campaign seems to have been a success. "Wow," responded one customer after Burger King reached out. "I'm surprised. What a service."

"What a gesture," responded another. One person simply commented: "Thanks -- Respect." 

Burger King's ad campaign is more than clever. It's an example of how brands can use emotional intelligence to build meaningful connections with customers.

Why Burger King's response is emotionally intelligent.

Emotional intelligence is the ability to identify, understand, and manage emotions. It includes developing the quality of empathy, which serves as a foundation of all great relationships.

In analyzing its own online customer service, Burger King realized it was falling short. Of course, it could have simply focused on how to improve and moved on. 

Instead, the company realized that if it was missing a golden opportunity, its biggest competitor might be too. By reaching out directly to McDonald's customers who were already left with a bad taste in their mouths, Burger King took advantage of the chance to sweep those customers off their feet. 

Then, Burger King took things a step further. 

The voucher for the free Whopper was delivered directly to customers via mobile phone, requiring customers to enter their phone number to receive their free gift. This gives Burger King the potential to continue courting those customers with special offers in the future.

In the end, Burger King gets the customer and their phone number--while providing good vibes in return.

So, remember, the next time you see a need to improve, take a look at your competitors. Are they lacking in the same areas? If so, improving your own service may open the door to helping solve your competitors' customers problems at the same time.