These trends tend to be "local" to some extent. Sometimes country based, but I've heard of cities where different schools had different messengers (back in the

These trends tend to be "local" to some extent. Sometimes country based, but I've heard of cities where different schools had different messengers (back in the ICQ/MSN etc. days). In the end, people use what their circle of friends uses. In Switzerland for example Threema is popular. In many countries you still can't really exist without Whatsapp. In China, Wechat. In Taiwan I believe you use Line if you want to have any friends (or reach businesses). In the US, iMessage with a fallback to SMS is popular, while it's rare in Europe because the SMS fallback would bankrupt you due to per-SMS charges.