> It is assumed that ad spending will always be worth it

This is mostly true. If it wasn't worth it, businesses wouldn't spend money on it. At my last startup we spent money on ads that were worth it, for us, so we stopped. We also found ads that were worth it, so we spent more.

> ad revenue will always increase

Ad revenue is cyclical, it's often the first thing to get cut and the first thing to come back, but it's always going to be there in some form barring a completely new economy.

> the market for digital advertising and targeted digital advertising in particular will always be large enough to support the behemoth that it is today.

Advertising shifts around from time to time (e.g. print->TV->online), but it seems unlikely that it's not going to be digital for the foreseeable future, and targeted will likely always outperform non-targeted. That's not to say it will stay at any particular company/property/app/etc. but unfortunately at this stage it's probably only going to concentrate and migrate from one behemoth to another like it has for most of the history of the industry.

(I work for Google but not in AI, search or ads)

It's OK if marketing spend goes down as long as digital continues to steal from non-digital advertising. Example: Advertising money spent on barely-targeted billboards and TV commercials could move to digital substitutes. This is some of what Google is trying to do with YouTube purchasing the rights for some NFL games.

Digital can steal all they want but if the thing you have attached to the ad ends up costing more than the ad gives you, market share means nothing. All this means is you lose even more money.

Weren't all these questions answered during the great recession, It wasn't easy but Google weathered the storm. Why is any upcoming recession going to be substantially different.

> But what happens when marketing spend goes down (as it does in a recession)? What happens when customers aren't willing to pay as much for your advertising product (as happens in a recession)? What happens when borrowed money can't be secured easily, and debts come due (once again, as happens in a recession)?

Typically - what happens is - central banks lower interest rates until they're negative in real yields - and people start spending like crazy again.

Who knows what will happen in the future. But that's been the previous playbook.

that only works if people A) still trust the underlying currency and B) you don't create hyperinflation. What happens in the future when the global economy isn't denominated in petrodollars?

Our government printed 10% of GDP as debt to hand out to people for doing nothing. This is almost the epitome of Monopoly money.

The worst that happened was 10% inflation - which is a FAR cry from hyperinflation.

We had negative real rates for a decade before Covid - and the worst that happened was ~7% home price appreciation.

We're not going to get anything resembling "hyper" unless this country basically becomes another country.

Thats because the rest of the world need US dollars to buy fuel. We and as such we have the defacto world currency. But that is changing, every years green renewable energy makes up a higher proportion world energy and we use less carbon based fuel requireing out currency less and less. Secondly we are seeing other world powers build out the infrastructure for international banking denominated in other currencies to avoid the US banking regulation and sanctions. at some point the Dollar wont have the level of utility and dominance that to allows the US to do that sort of currency manipulation without consequences.

So how come Europe could do the same thing and the UK and Canada, and they each also only saw 10% inflation?