With birthrates on the decline in Denmark, Spies, a Danish travel agency came up with a very unusual way to promote travel, among other activities at the same time with the suggestively-named 'Do it for Denmark' campaign.
Birthrates in Denmark are at a 27 year low, meaning there aren't enough babies being born to support its aging population. However, couples are about 46% more likely to engage in sexual activity while on vacation, so Spies created a campaign around this idea.
On the Do it for Denmark site, there's even an ovulation calendar, so that trips can be planned around the time a woman is most likely to get pregnant. About nine months after booking a trip, if couples can prove that they conceived while on that holiday, they will win three years worth of baby supplies, plus a family-friendly vacation.