

It does make sense for Signal as this is a free app that does not make money from advertising. It makes money from donations.
So every single message, every single user, is a cost without any ongoing revenue to pay for it. You’re right about the long run but you’d need the cash up front to build out that infrastructure in the short term.
AWS is cheap in the sense that instead of an initial outlay for hardware, you largely only pay for actual use and can scale up and down easily as a result. The cost per user is probably going to be higher than if you were to completely self host long term, but that does then mean finding many millions to build and maintain data centres all around the world. Not attractive for an organisation living hand to mouth.
However what does not make sense is being so reliant on AWS. Using other providers to add more resilience to the network would make sense.
Unfortunately this comes back to the real issue - AWS is an example of a big tech company trying to dominate a market with cheap services now for a potential benefits of a long term monopoly and raised prices in the future. They have 30% market share and already an outage by Amazon is highly disruptive. Even at 30% we’re at the point of end users feeling locked in.







It’s about short term vs long term costs, and AWS has priced itself to make it cheaper short term but a bit more expensive long term.
Companies are more focused on the short term - even if something like AWS is more expensive long term, if it saves money in the short term that money can be used for something else.
Also many companies don’t have the money upfront to build out their own infrastructure quickly in the short term, but can afford longer term gradual costs. The hope would be even though it’s more expensive, they reach a scale faster where they make bigger profits and it was worth the extra expense to AWS.
This is how a lot of outsourcing works. And it’s exacerbated by many companies being very short term and stock price focused. Companies could invest in their own infrastructure for long term gain, but they often favour short term profit boosts and cost reduction to boost their share price or pay out to share holders.
Companies frequently so things not in their long term interests for this reason. For example, companies that own their own land and buildings sell them off and rent them back. Short term it gives them a financial boost, long term it’s a permanent cost and loss of assets.
In Signals case it’s less of a choice; it’s funded by donations and just doesn’t have the money to build out it’s own data centre network. Donations will support ongoing gradual and scaling costs, but it’s unlikely they’d ever get a huge tranch of cash to be able to build data centres world wide. They should still be using multiple providers and they should also look to buildup some Infrastructure of their own for resilience and lower long term costs.