[fnomnom]

the main online selling plattform in germany (ebay-kleinanzeigen) has a messenger integrated that everybody just uses for this reason. almost everyything else happens in whatsapp. yes youhave some people on signal/threema/telegram but virtually everybody has whatsapp.

[vinay427]

Yep, some Swiss platforms have a similar messaging system but others (e.g. Ricardo.ch, probably the most popular?) just offer contact information instead.

It might also help that it's increasingly common to pay over the TWINT mobile payment system created by Swiss banks for which mobile numbers remain the primary identification method for private users, not to mention SMS messages used for transaction confirmations or login codes. Given the default option of a phone number for many of these private sales, an SMS is probably more straightforward than adding a new contact to use another app.