"The falling birth rate in the future will be a problem for us. That's pretty valid, but it is a humor technique," Lundgren told CNBC in a phone interview.
"The benefit is of course the engagement from the public, and it's our way to stick out in a generic travel market," she explained.
Spies' webpage claims a sunny activity holiday boosts the average Dane's sex life by 51 percent. "But what you might not know is that exercise with your partner increases the sex drive even further," the video ad says.
It's not the company's first foray into rather racy territory. "Do It for Mom" is a continuation of Spies' "Do It for Denmark" competition last year, which doled out prizes for mothers who were able to prove they became pregnant during a "romantic" city break — booked through Spies of course.
Prizes ranged from a year's worth of diapers, a baby buggy and a resort holiday for the new family.
This time around, Spies could be spending a good amount of cash, with up to 1000 Danish krone towards every client's holiday booked before the December 1 deadline. But Lungren insists the campaign is worth its weight, and despite no upper limit, is accounted for in Spies' discount budget.
Most participants are expected to head to Mallorca in Spain, the Canary Islands, Greece, or Turkey as part of the deal.
Anyone, not just childless Danes can take part, as long as they fly out of Denmark, Lundgren said.