Of every line item on a cloud invoice, egress is the one with the widest margin and the clearest purpose. It costs the provider close to nothing to deliver, it is priced as if bandwidth were scarce, and it quietly does the most important job in the whole pricing model: it keeps you from leaving.
How the tax works
Egress is the charge for moving your own data out of the cloud — to your users, to another provider, sometimes just to another region of the same provider. It is metered per gigabyte, and the rate has stayed remarkably stable even as the wholesale cost of bandwidth has fallen for years.
The effect compounds. The more successful your application, the more data it serves, and the larger the egress bill grows — independent of how much you are actually storing or computing. Teams routinely discover that serving their data costs more than producing it.
Why it is really a lock-in mechanism
Consider what egress does to a migration. To move a large dataset to a lower-cost provider, you first have to pay the current provider to let the data out. The bigger your data, the more expensive it is to leave — which means the most committed customers, the ones with the most data, face the highest exit cost. The tax scales with exactly the thing that should give you leverage.
The genius of egress pricing is that it turns your own data into a hostage. The more you have, the harder it is to take it with you.
What it actually costs to move bytes
If you own your network and your transit, moving data out is not a metered product — it is just traffic on a link you already pay a flat rate for. There is no per-gigabyte cost to pass on, because there is no per-gigabyte cost to begin with. The only reason egress is a line item is that it can be.
This is why owned infrastructure can do something the hyperscalers structurally will not: not charge for egress at all. It is not a promotion or a loss leader. It reflects what the resource actually costs when you are not pricing it to fund a control plane and discourage departures.
The honest version
There are real constraints worth stating plainly. Internet upstream from any single facility is finite and shared; a sustained, dedicated multi-gigabit stream to the public internet is a different product than a generous monthly transfer allowance, and we are explicit about that distinction. What does not exist is a per-gigabyte penalty for reading your own data, and a dedicated uplink is available when guaranteed external throughput is the requirement.
For storage-heavy and read-heavy workloads, removing the egress tax is the single largest change you can make to a cloud bill. It is the first thing Smelt storage removes, and the reason the cost comparison is not close.