Thailand ranks in the world's top 10 for social media usage, with video becoming more popular and entertainment the topic most talked about on social media.
Facebook's policy tweak to reduce its reach will cause brands and advertising spending to rise 27% in 2018, while Instagram and Twitter will gain more traction from brands, said Pnern Asavavipas, chief executive of Onebit Matter Co.
"In 2017, there were 49 million Facebook users in Thailand, growth of only 4% year-on-year, the lowest on record," Mr Pnern said at the Thoth Zocial OBVOC in Thailand Awards 2018.
"Instagram had 13.6 million users, growth of 24%, and Twitter had 12 million users, 33% growth," he said.
Thailand ranked eighth in number of Facebook users, with India, the US and Indonesia taking the top three.
Moreover, the number on Facebook Messenger was flat, with 26 million Thai users, ranking seventh globally, while the US, India and Brazil were tops.
"No growth in Facebook Messenger users is in line with the maturity of Facebook users," Mr Pnern said.
The peak time for Facebook use in Thailand is 6pm-11pm. Bangkok has 24 million Facebook users, followed by Chiang Mai and Chon Buri.
Mr Pnern said the company also foresees that Facebook's algorithm change will reduce reach, finding that brands need to spend 27% more to make the same level of engagement per post in 2018.
"Statistics found that when brands increase their post frequency by 52%, engagement increases by only 12%, so engagement per post has contracted 27%," Mr Pnern said. "Brands and advertisers have to spend more or work harder to get audience engagement."
Onebit Matter also found that the top three content formats by engagement were videos (2,556 engagements per post), photos (1,273) and links (1,199).
Mr Pnern said Thailand ranked 14th in terms of Instagram users in 2017, while the US, Brazil and India were the top three.
Instagram users are most engaged on the weekend; peak hours are 6pm-10pm. They prefer to post images (71%), carousel ads (24%) and videos (5%).
Mr Pneran said Twitter users seem to be night owls, with peak activity shifting to 1am in 2017 from 2016 peak hours of 8pm-midnight.
The company also compared Twitter users in 2016 with 2017, finding that Twitter not only increased its user base but also gained more active users.
Twitter users tweeting brands increased by 124% last year. Total branded retweets rose by 101%.
This year, brands might diversify media spending to Twitter and Instagram because of their high engagement or increase Facebook payments to boost reach, Mr Pneran said.
Kla Tungsuwan, chief executive of Thoth Zocial Co, said brands needs to focus on new key measurements, not just number of likes, but they have to calculate spending for customers' acquisition costs.
"Social media can make brands succeed or fail, and they have to use data analytics and engage users with target behaviours suited to brands," Mr Kla said.