> Servers: $2.9 million dollars per year.
> Registration Fees: $6 million dollars per year.
> Total Bandwidth: $2.8 million dollars per year.
> Additional Services: $700,000 dollars per year.
Signal pays more for delivering verification SMS during sign-up, than for all other infrastructure (except traffic) combined. Wow, that sounds excessive.
https://www.cnn.com/2023/02/18/business/twitter-blue-two-fac...
Previous Twitter employees have said that this is incorrect. Because Twitter began as an SMS-only (and then SMS-first) application (remember 40404?), they very early on established direct-connection infrastructure for sending SMS, meaning that they have a marginal cost of literally $0.00/message in most markets. Twitter still has to maintain that infrastructure, because they didn't get rid of SMS 2FA - they just restricted it to Twitter Blue users, so the overhead is still the same.
Almost nobody else who delivers SMS today has that infrastructure, because it doesn't make sense for most services to build.
The only place where Twitter was paying significant amounts for SMS was due to SMS pump schemes, which is a consequence of Twitter gutting its anti-spam detection, resulting in them paying for SMS pumping which was previously blocked.
I am very, very interested to understand how that works, because without more detail or sources I'm calling bullshit. I definitely understand how Twitter could have greatly reduced their per-message fee with telecom providers, but at the end of the day Twitter is not a telecom and is still at the mercy of whoever is that "last mile" for actually delivering the SMS to your phone, so I don't understand how they have no marginal cost here. Happy to be proven wrong.
For something like Twitter where you could post by SMS, the balance of traffic might have been such that giving Twitter free outbound SMS was balanced by the charges incurred by customers sending to Twitter's shortcode. Or it might just be balanced by increased customer happiness when they can use the product more effectively.
If the carrier doesn't run their own messaging infra, they might be paying their IT provider on a per message basis, and might not be able or willing to set the messaging rate to zero.
For a use case where SMS is used to show control of a phone number, getting a zero cost direct route is a harder sell, but it can happen if the routing through aggregators is poor and the carrier is concerned about that, or if there's some other larger agreement in play.
I ran the engineering side of carrier integrations at WhatsApp. Carriers wanted to sell data plans with special pricing for data with WA and use WA branding in advertising, because it attracted customers that might later convert to a bigger general purpose data plan. As part of that, we would ask for zero rated SMS to their customers for verification. When it was available, it was generally faster and higher success vs sending messages through an aggregator.
We also had some, usually small, carriers approach us asking us to set up direct routes to them for verification, because their customers would not always receive our messages when we sent through an aggregator. Early in my career at WA, we would just send these carriers to our aggregator contacts, and often things would get linked up and then we'd still pay $/message but it would work better. As we got a little bigger and built support for direct routes anyway, it was usually not too hard to set up a direct connection and then there'd be no cost for that carrier. Messing around with IPSEC VPNs and SMPP isn't fun and the GSMA SOAP messaging APIs are way worse, but once you get the first couple implementations done, it becomes cookie cutter (and FB had built way better tools for this, and a 24/7 support team, so I never had to be up, on the phone with telco peeps at 3 am kicking racoon or whatever ipsec daemon we were running until it finally connected)