The power of viral social media can be astounding at times, and German automaker BMW has now proven that in China, it’s possible to invent a whole new holiday just from the influence of a few prominent microbloggers.

On July 12, a viral movement that swept over Chinese microblogging platform Sina Weibo saw more than 300,000 users pour out their deepest regrets for the world to read in 140-character form. Using the hashtag #Ctrl Z Day#, users participated in what they believed to be a “worldwide day of regret” that takes place “on the second Friday of every July,” in which they took to the internet to state what parts of their life that they wish they could reverse if life had a “Ctrl Z” function, which is the “undo” command on PCs.

So, if this was a “global” day of regret, why have you never heard of it before? The answer is simple: because BMW made it up four days earlier as part of an elaborate marketing campaign to promote its Z4 model.

News of the faux holiday spread like wildfire on Chinese social media starting on July 8, when a concentration of Sina Weibo’s “key opinion leaders” (KOLs) began tweeting about the event, encouraging followers to take part in this “worldwide” movement. What followers didn’t know at the time was that BMW was orchestrating the whole thing, hoping that the KOLs’ popularity would create organic viral magic. Some of the KOLs included a glum-looking graphic along with their post, which is shown in the screenshot below.

BMW’s bet paid off, as the campaign certainly did go viral. By the time July 12 had rolled around, netizens’ remorseful outpourings were a fixture on Weibo, and major Chinese media outlets were reporting on the holiday. “In the internet age, wouldn’t you know that a holiday for everything is becoming trendy?” quipped Xinhua. The day was also discussed on the CCTV and Global Times Weibo accounts, although it’s not clear if BMW had any role in their reports.

Weibo users’ comments ranged from earnest, heartfelt statements to sharp political satire. While some had very general regrets, such as wishing they “did not work as hard,” others had poignant and heartbreaking stories of unrequited love or the loss of close family members. One user stated, “I would use Ctrl Z on June 27, 2005, the day my grandma passed away. I was in junior high and stupidly obeyed my parents who told me to continue studying for my final exam instead of going to see my grandma for one last time.”

Meanwhile, several netizens used the opportunity to sarcastically lodge criticisms against the Chinese government, many of which went viral. Prominent blogger Liu Jishou, who has over 5.6 million followers, took a jab at the the government’s previously botched campaign against Apple from this spring, stating, “If I had another chance, I wouldn’t post at 8:20.” He was referring to the now infamous incident during the height of the government’s anti-Apple campaign in which one celebrity posting criticisms of Apple left instructions to post the statement at 8:20 in the text, showing that the government had likely coordinated the whole thing. Liu’s post alone received more than 27,000 retweets.

On July 15, BMW revealed itself as the force behind the campaign, using the opportunity to both provide a philosophical lesson on life and regret, as well as market its Z4 car model. Its post featured the gray and dreary graphic from the original KOLs’ posts juxtaposed with an idyllic shot of a red Z4 zooming down a beautiful coastal road. “Life is not a flat road,” read the post. “There will inevitably be setbacks, a few of which you will have no choice over, but regret can’t reverse them. Rather than remembering the past, it is better to look forward to the future. Life doesn’t have a Ctrl Z. Control Z4: drive and have no regret!”

Responses to the campaign on its Weibo thread were positive, with users transmitting the life advice, praising the creativity of the ad, and discussing what they liked about the car. “My new desktop background. This comprehensive campaign really struck popular sentiment. Life doesn’t have a Ctrl Z!” said one impressed user. “Car brands are coming up with more and more entertaining marketing,” said another. Others expressed admiration for the Z4, saying that they “love” the way it looks and calling it “gorgeous.” A separate thread on Adquan describing the way in which the “holiday” went viral also saw positive statements about the campaign’s inventiveness. “This could be the greatest marketing campaign since the beginning of history!” exclaimed one user.

The success of the campaign relied on users’ trust in the KOLs’ statements and willingness to earnestly participate, and it appears to have avoided making users feel emotionally manipulated after pouring their hearts out about painful memories when they did not know that it was a car company calling on them to do so. In addition, the propensity of KOLs to utilize viral trends to make biting political commentary was equally, if not even more instrumental in propelling the campaign’s exposure. If a similar campaign were carried out elsewhere, such as in the United States, the reaction may have been different, but most users seem to have found BMW’s strategy to be clever and amusing.