If you don't know about the Thailand Stand Up Challenge, #thailandstandupchallenge or even #strongertogether hash-tags on social media, you are behind the times.
If you have not received the challenge from your friends on Facebook or Instagram, you're missing something on Thailand's social media scene.
The challenge has gone viral, requiring a social-media user to share a photograph of an interesting destination or an item that is unique to Thailand for three days, with the privacy setting of the post on public, then challenge others to do the same. There is no limit to the number of people the user can challenge.
The challenge was started three days after the Aug 17 bombing at Erawan Shrine, by a Kasetsart University student, who challenged his Facebook friends to share their photos and experiences from Thai tourist destinations online.
Dhanapol Phanngam, a fourth-year student at Kasetsart University's forestry faculty, said he created the challenge on Facebook as an act against the violence exhibited by the bombing. He wanted to show Thailand's tourism sites are still beautiful and peaceful.
He told Bangkok Post he posted a picture of himself taken in Kanchanaburi province on Facebook and invited others to tell their friends that people in Thailand were not shaken by the blast. The pictures would demonstrate on social networks that Thailand remained beautiful for tourists.
In only a few weeks the challenge became the talk of the town, prompting Thais to display lovely Thai sites, restoring tourist confidence in the process.
As of Oct 1, Instagram had 26,597 posts with #thailandstandupchallenge and more than 15,000 posts tagged #strongertogether. Many more thousands have been posted on Facebook.
Mr Dhanapol explained to accept the challenge, a person must post one picture of himself or herself per day for three days, identify the place and attach the hashtags #thailandstandupchallenge or #strongertogether. The status of the posted pictures must be set to public, and each participant must invite friends to do the same for 24 hours.
Supaporn Sukanthong, 30, received the challenge from her friends on Facebook. She shared photos from her travel experiences online and sent the challenge to four friends immediately.
"I want to share my travel experiences through my photos to inspire others to travel in Thailand. Our country has a lot of beautiful places to visit. I wanted to pack my bag and travel right away when I saw photos posted by my friends for the challenge," she said.
Mr Dhanapol said the Tourism Authority of Thailand's governor, Yuthasak Supasorn, sent him a message on Facebook admiring his idea for the challenge.
The success of the tourism challenge has spurred a new hashtag #thaifoodchallenge, which was created to promote food activities.
"It's a good idea to use viral marketing to promote tourism and food. I'm so glad to see young people participate in this kind of campaign," said Mr Yuthasak.
Viral marketing is a great way to promote a product or issue, but it can be difficult to make the campaign go viral. The idea of a challenge plays on human nature as many people love a contest. Moreover, it's a way for Thais to share their feelings and help each other out when the country faces a crisis.
It doesn't hurt that Thais are crazy about social media, he said.
A survey by the Digital Advertising Association of Thailand showed Facebook was the leader for social media in Thailand with 30 million users, followed by YouTube with 26.2 million users. Twitter and Instagram had 4.5 million and 1.7 million users, respectively.
Some 19.8 million Facebook users log on everyday, while 28 million are active on the internet on mobile devices.