If every Snapchat user paid $2/month, wouldn't Snapchat have decent revenue? For some service the infrastructure might cost a lot, but I don't think it applies

If every Snapchat user paid $2/month, wouldn't Snapchat have decent revenue? For some service the infrastructure might cost a lot, but I don't think it applies to Snapchat (it's a very "ephemeral" photo-sharing platform, after all). Another way would be to charge for every photo you upload. Those that share more pay more, which would make sense.