Facebook has a few moves here. By doing a limited test in both Thailand, a high ad engagement, growing market [1][2], and Australia, a lower-engagement but high-spend market [3], they can gauge how advertisers respond in two very different markets, while keeping the more numerous [4] North American, Indian, and Brazilian users out of the fray -- and most reputational fallout -- for now.
There is still a small possibility that they'll renege on this plan. Google, whose rivalry with Facebook in the area of messaging is longstanding [5], has largely squandered their potential in this space with a confusing product strategy, but have remained a dominant force in advertising thanks to Search, Youtube, Maps, and Android. Google has recently shuffled up its messaging lineup again by rebooting Google Voice, still having Hangouts, and pushing Duo and Allo, but Facebook provides a unified experience by having all of this in one app. Facebook is no doubt gambling on the fact that any user fallout about ads in Messenger won't be severe enough to cause an exodus of users to a competitor who poses a threat -- and right now, it's unclear if Google poses a threat or just continues to flail ineptly.
Meanwhile, Snapchat doesn't pose a serious risk to Messenger, because Instagram has suitably cloned all of its features while also retaining the core product around curated photos; WhatsApp is a serious player in Brazil and India, is of course now run by Facebook in a brilliant example of market positioning; Skype has hemorrhaged marketshare due to Microsoft's (mis-)management; a few other smaller players target niche audiences (e.g. pseudonymous harder-to-monetize users, gamers, privacy-conscious users).
This leaves their biggest threats European and Asian-operated platforms like WeChat, LINE, Viber, and Telegram. WeChat dominates the Chinese market due to various home turf advantages, while Telegram is popular in the Cyrillic world and MENA, Viber in Europe and Israel, and LINE in Japan. So far, none of them have challenged Facebook in its core markets.
There is still a small possibility that they'll renege on this plan. Google, whose rivalry with Facebook in the area of messaging is longstanding [5], has largely squandered their potential in this space with a confusing product strategy, but have remained a dominant force in advertising thanks to Search, Youtube, Maps, and Android. Google has recently shuffled up its messaging lineup again by rebooting Google Voice, still having Hangouts, and pushing Duo and Allo, but Facebook provides a unified experience by having all of this in one app. Facebook is no doubt gambling on the fact that any user fallout about ads in Messenger won't be severe enough to cause an exodus of users to a competitor who poses a threat -- and right now, it's unclear if Google poses a threat or just continues to flail ineptly.
Meanwhile, Snapchat doesn't pose a serious risk to Messenger, because Instagram has suitably cloned all of its features while also retaining the core product around curated photos; WhatsApp is a serious player in Brazil and India, is of course now run by Facebook in a brilliant example of market positioning; Skype has hemorrhaged marketshare due to Microsoft's (mis-)management; a few other smaller players target niche audiences (e.g. pseudonymous harder-to-monetize users, gamers, privacy-conscious users).
This leaves their biggest threats European and Asian-operated platforms like WeChat, LINE, Viber, and Telegram. WeChat dominates the Chinese market due to various home turf advantages, while Telegram is popular in the Cyrillic world and MENA, Viber in Europe and Israel, and LINE in Japan. So far, none of them have challenged Facebook in its core markets.
[1] http://www.tnsglobal.com/thailand-digital-ad-spend-report [2] https://www.emarketer.com/Article/Facebook-Ad-Spending-Domin... [3] http://www.smartinsights.com/digital-marketing-around-the-wo... [4] https://www.statista.com/statistics/268136/top-15-countries-... [5] https://news.ycombinator.com/item?id=13465483