EMarketer said United Kingdom trends were closely tracking those in the USA, where Snapchat set to gain the most new users in the coveted 12 to 17 age bracket this year.
Facebook is still adding monthly users, but they are mainly from older age groups - and not all the young people leaving the platform are going to Facebook-owned Instagram, which is not growing as fast as Snapchat.
Despite its problems with young people, overall, Facebook is expected to reach 86.2 per cent of social network users in 2018 - way ahead of 49.9 per cent for Instagram, 42.7 per cent for Snapchat, and 33.5 per cent for Twitter.
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The opposition is calling for a boycott of the vote, after serious challengers were either arrested or forced to quit the race. Some 2,300 representatives from the private sector, including from more than 100 American companies, are slated to attend.
Expect more posts by people who think that LOL stands for "Lots of Love", as the number of oldies on Facebook surges and teens jump ship for the happy lands of Snapchat.
Meanwhile, more over-55s are signing up, with half a million new users expected to join by the end of the year. At the same time, eMarketer also predicts that the number of users aged between 12 and 17 will see a 5.6 percent decline while the number of users aged 18 to 24 will drop by 5.8 percent. Facebook remains the biggest social media platform, however, with the number of regular users of the network hitting 1.54 billion - or 62.2% of all social media users.
Over-55s will become the second-biggest group on the network, as 700,000 people aged 12 to 24 defect to services such as Snapchat, according to predictions by eMarketer. "But not all of those users are migrating to Instagram". Snapchat is expected to add 1.9 million users in this age group of 24 and younger.
This is the first time its predicted a decline in that age group. Eighty-nine percent were using Snapchat, up from 29 percent four years ago. The social network is expected to reach 169.5 million USA users this year, marking just a slight increase of almost 1 percent compared to 2017.