If you ask people why they are using AI (or want other people to use it) you get a ton of different answers. Typically none of them contain the real reason, which is that using AI is dirt cheap. Between paying a fair amount to get something done and paying very little to give off an impression that the work has been done, the latter tends to win.

The reason AI is so cheap is that it is being paid by investors. And the one thing we know for certain about those kinds of people is that they expect to get their money back. Multiple times over. This might get done by selling the system to a bigger fool before it collapses, but eventually someone will have to earn that money back from actual customers (or from government bailouts, i.e. tax payers).

I'm not an economist and took a grand total of one economics class in the university, most of which I have forgotten. Still, using just that knowledge we can get a rough estimate of the money flows involved. For simplicity let's bundle all AI companies to a single entity and assume a business model based on flat monthly fees.

The total investment

A number that has been floated around is that AI companies have invested approximately one trillion (one thousand billion or 1e12) dollars. Let's use that as the base investment we want to recover.

Number of customers

Sticking with round figures, let's assume that AI usage becomes ubiquitous and that there are one billion monthly subscribers. For comparison the estimated number of current Netflix subscribers is 300 million.

Income and expenses

This one is really hard to estimate. What seems to be the case is that current monthly fees are not enough to even pay back the electricity costs of providing the service. But let's again be generous and assume that some sort of a efficiency breakthrough happens in the future and that the monthly fee is $20 with expenses being $10. This means a $10 profit per user per month.

We ignore one-off costs such as buying several data centers' worth of GPUs every few years to replace the old ones.

The simple computation

With these figures you get $10 billion per month or $120 billion per year. Thus paying off the investment would take a bit more than 8 years. I don't personally know any venture capitalists, but based on random guessing this might fall in the "takes too long, but just about tolerable" level of delay.

So all good then?

Not so fast!

One thing to keep in mind when doing investment payback calculations is the time value of money . Money you get in "the future" is not as valuable as money you have right now. Thus we need to discount them to current value.

Interest rate

I have no idea what a reasonable discount rate for this would be. So let's pick a round number of 5.

The "real-er" numbers

At this point the computations become complex enough that you need to break out the big guns. Yes, spreadsheets.

Here we see that it actually takes 12 years to earn back the investment. Doubling the investment to two trillion would take 36 years. That is a fair bit of time for someone else to create a different system that performs maybe 70% as well but which costs a fraction of the old systems to get running and operate. By which time they can drive the price so low that established players can't even earn their operating expenses let alone pay back the original investment.

Exercises for the reader