Network effects aren't a big deal when it comes to messaging. There was a time when people thought iPhone wouldn't be able to overcome Blackberry because everyone was on BBM. In the last couple decades we've seen people go from ICQ to AIM/Yahoo/MSN to Google Talk to Skype to Facebook Messenger to BBM to Whatsapp/iMessage/Instagram, with dozens of smaller options like Kik, Viber, Line, Signal, Telegram all hanging around. It doesn't take much to cause another shift in the space.
That sounds nice, but in reality most of my extended friend group has migrated to WhatsApp over the last 10 years and is unlikely to change anytime soon. Interoperability would be nice (like we used to have) but that will never happen until Apple stops using their lack of interoperability as a way to ostracize young people and sell more phones.
We are off those because of multi messanger platforms made switching to the "hot new thing" very low friction. It was only once mobile came along that the playing field narrowed so much.
Current networks have way more lock in than back in the day.
I don't find there is much network effect for one on one messaging. I have to use a few different apps to talk to all my friends, it's not a big deal to switch to/from Signal or Whatsapp. With groups it's more effort.
This does not match my experience in Germany. If somebody gives you their phone number it is just expected that you can reach them on WhatsApp and i have yet to meet anyone that doesn't use WhatsApp.
That seems true throughout the most of the Western world, excluding the US. I have a big WhatsApp network, but that's by virtue of living in SF and NY. Without big immigrant/expat/world-traveler communities, I think most of the US just uses iMessage or regular text.
It's easy to have multiple chat apps in parallel though, each with their own network.
Ads will make more people Signal-curious, or even drive people back to text messages. The average person who switches will convince a non-zero number of their contacts to come with them. The shift will start gradually. Think of Skype, which at one point everyone I knew was on. That network didn't protect them from being replaced by competitors.
People are also increasingly worried about retaliation from the government for their supposedly free speech, which has already driven a few people I know to secure alternatives that aren't operated by Trump allies.
