Social media can be a great tool for marketing in the moment. Also the worst.

Will they? Or won’t they? For months speculation was rife over whether Chinese actors Fan Bingbing and Li Chen would come together as a couple or not. Finally on May 28^th all speculation was laid to rest when Li Chen, star of the popular TV show Running Man China, posted a photo of the two together with the tell-all caption “wo men”, (which means “us” in English) on Weibo, China’s Twitter-equivalent. Fan Bingbing, an acclaimed actress herself who played the role of a mutant in the Hollywood flick X-Men: Days of Future Past, was quick to repost the photo, and now all of China could relax because their favorite on-screen couple was actually a couple.

Li Chen’s post got 1 million reposts and 3 million likes, becoming one of the most interactive Weibo posts ever.

Meanwhile the hashtag “#wo men#” (on Weibo you need two hashtags) or “#us” has gone viral. It has been used over a million times.

For one, it prompted other lovebirds to start showing off their relationship status online. Before long, tens of thousands of internet users posted photos with their beloved ones with the hashtag “#us”. Even the United Nations’ official Chinese Weibo account posted a picture Secretary General Ban Ki-moon and his wife with the hashtag “#us”!

Smart companies like Xiaomi, JD.com and Nubia smelt a unique “marketing in the moment” opportunity here. Lei Jun, Xiaomi’s CEO who has 12 million fans on Weibo, reposted Xiaomi official account’s “#us” photo which features a black and a white Mi phone leaning on each other. E-commerce giant JD.com posted an “#us” picture of its mascot dog sniffing Xiaomi’s Mi Bunny mascot, showcasing JD.com’s partnership with Xiaomi. Similarly, Chinese smartphone manufacturers Meizu and Nubia did their own versions of “#us”. For these companies, it made complete sense. They were able to ride piggyback on a hot topic, and be seen as trendy and hip. Latching on to a viral topic is a cost-effective way of marketing.

The idea of marketing in the moment is not new. Several brands have used this as an effective marketing strategy. When the horse meat scandal rocked UK, Mini Cooper came out with an ad with the tagline: "Beef. With a lot of horses hidden in it." In April 2015, a one-line resignation letter by a high school teacher in China went viral on social media: “The world is so big; I want to go out there and see”. The message resonates with many white collar workers. Luxury car maker Infiniti leveraged the message with an ad that said, “If you don’t have the courage to go, you will never see miracles”, urging people to pursue their real dreams. You would remember the iPhone bendgate problem. LG brilliantly used its rival's problems for its own gain.

For football fans, the 34-minute blackout during the 2013 Super Bowl might ring the bell. The blackout certainly was a big embarrassment for the organizers, but cookie brand Oreo, quite literally, made hay when the sun did not shine. “Power out? No problem. You can still dunk in the dark,” it tweeted. The post has been retweeted 15,581 times thus far.

During the 2014 Sochi Winter Olympics opening ceremony, a display meant to show snow flakes turning into Olympic rings malfunctioned, and one of the five snowflakes, somewhat embarrassingly, didn’t expand into the Olympic ring. Energy drink Red Bull promptly came up with a post: “What opened is energy; what remained unopened is potential” with five cans of Red Bull forming the Olympic logo.

Social media can be the best of tools to market, but also the worst. If executed well and quickly enough, “in the moment marketing” can be extremely rewarding. But if brands take the approach without thorough considerations, it could backfire. So when has “in the moment marketing” failed?

Earlier in 2015, tweeples were outraged after a hotel chain, The Hoxton, promoted its Paris hotel on Twitter using the “#jesuischarlie” hashtag (with the hashtag spelt wrong incidentally) trying desperately to latch on to the Charlie Hebdo massacre. The Hoxton was criticized for its lack of sensitivity and called “despicable beyond belief” and they deleted the tweet and apologized soon.

Later, Uber found itself in a PR nightmare, after it raised prices for rides during the Sydney siege. Uber claimed that the price surge kicked in automatically because the design of its algorithm, which was supposed to encourage drivers to go to high-demand areas, and it’s a mistake to not stop it “immediately”. After being heavily picked on, Uber started to offer free rides to get people out of the city and expressed that they were “truly sorry” for the price surge.