The only thing these companies sell are tokens. That's their entire output. OpenAI is trying to build an ad business but it must be quite small still relative to selling tokens because I've not yet seen a single ad on ChatGPT. It's not like these firms have a huge side business selling Claude-themed baseball caps.
That means the cost of "inference" is all their costs combined. You can't just arbitrarily slice out anything inconvenient and say that's not a part of the cost of generating tokens. The research and training needed to create the models, the salaries of the people who do that, the salaries of the people who build all the serving infrastructure, the loss leader hardcore users - all of it is a part of the cost of generating each token served.
Some people look at the very different prices for serving open weights models and say, see, inference in general is cheap. But those costs are distorted by companies trying to buy mindshare by giving models away for free, and of those, both the top labs keep claiming the Chinese are distilling them like crazy including using many tactics to evade blocks! So apparently the cost of a model like DeepSeek is still partly being subsidized by OpenAI and Anthropic against their will. The cost of those tokens is higher than what's being charged, it's just being shifted onto someone else's books. Nice whilst it lasts, but this situation has been seen many times in the past and eventually people get tired of having costs externalized onto them.
For as long as firms are losing money whilst only selling tokens, that means those tokens are selling at a loss. To not sell tokens at a loss the companies would have to be profitable.
• Inference used for training? Modern training pipelines aren't just gradient descent, there's a ton of inference used in them too.
• Gradient descent itself?
• The CPUs and disks storing and managing the datasets?
• The web servers?
• The people paid to swap out failed components at the dc?
Let's say you try and define it to mean the same as unit economics - what does it cost you to add an additional customer vs what they bring in. There's still no way to do this calculation. It's like trying to compute the unit economics of a software company. Sure, if you ignore all the R&D costs of building the software in the first place and all the R&D costs of staying competitive with new versions, then the unit economics look amazing, but there's still plenty of loss-making software startups in the world.
Unit economics are a useful heuristic for businesses where there aren't any meaningful base costs required to stay in the game because they let you think about setup costs separately. Manufacturing toys, private education, farming... lots of businesses where your costs are totally dominated by unit economics. AI isn't like that.
> Does it include:
> Inference used for training? Modern training pipelines aren't just gradient descent, there's a ton of inference used in them too.
No because this is training and not inference. Just like how R&D costs for a drug aren't part of COGS either.
> Gradient descent itself?
No
> The CPUs and disks storing and managing the datasets?
Yes
> The web servers?
Yes
> The people paid to swap out failed components at the dc?
Yes to the extent they are swapping for inference and not training. If the same employees do both then the accountants will estimate what percent of their time is dedicated to each and adjust their cost accordingly.