[jedberg]

They already own those IPs and there is no ongoing fee to keep owning them. So everything they make is profit since they costs have already been accounted for.

Like if you already owned a piece of land and let people rent houses on the land, and now you're charging them extra rent per square foot of land. You already own the land, so it's pure profit, because before you were including the cost of land in the houses. But of course the metaphor breaks down because at AWS you can move to IPv6 to avoid the cost, but you can't move the house off the land.

[crazygringo]

That is not correct.

IP addresses are intangible property and, at this scale, their cost would probably be amortized over a period of e.g. 20 years.

For accounting (and tax purposes), it's not one big up-front cost where everything that follows is pure profit.

Just because costs happen before income, it doesn't follow that all the income is profit. You have to look at things over the expected useful time frame of property.