[hnbad]

If you're looking to expand to continental Europe, I'd strongly suggest WhatsApp if you want to stick to the SMS-style interactions. The only SMS messages I get are one-time verification codes and roaming notifications. Everything else is usually spam.

[techdiff]

Good info, thank you! We were pushing on WhatsApp for South America and Asia (we tested through Singapore, Philippines, Myanmar, Indonesia and Malaysia but pulled back on the region because SMS carrier support is so varied. New Zealand is a nightmare too. But being well used in EU, we might need to bump this up the roadmap.

[hnbad]

Telegram and Signal have been gaining some traction in Germany (don't know about other EU countries) but the former saw most of its adoption among "COVID skeptics" and has had some kind of falling out with the German government over refusal to cooperate with the authorities, so its reputation is mixed and its legal status going forward is unclear. Signal doesn't seem to suffer the same reputation but doesn't seem to control much market share.

WhatsApp is ubiquitous, at least among millenials and above. I'm not sure what the zoomers are up to. It's unavoidable for parents especially because parent groups exist for everything from kindergarten to sports. Usage may decline in the years to come over Meta's data protection issues but there's no end in sight.