If there is to be no sale, then is it really advertising at all? If I "advertise" that I own a thing with no intention of selling that thing, then laws about honest advertisement don't apply to me.

My car (not for sale) has a nuclear reactor and can travel through time.

yes

No, not in a sense that triggers truth in advertising laws.

If you advertise a product without intent to sell, you're also breaking truth in advertising laws: you're selling vaporware.

FTC

https://www.ftc.gov/business-guidance/resources/advertising-...

Counter-example:

> What can my company do if a competitor is running an ad that I think is deceptive?

> Explore your legal options under federal and state statutes that protect businesses from unfair competition. For example, the Lanham Act gives companies the right to sue their competitors for making deceptive claims in ads.

> Are advertising agencies subject to the FTC Act?

> Yes. In addition to the advertiser, the advertising agency also may be held legally responsible for misleading claims in ads. Advertising agencies have a duty to make an independent check on the information used to substantiate ad claims. They may not rely on an advertiser's assurance that the claims are substantiated.

I don't see anything about false advertising requiring a sale.