system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How can most competing companies (insurance, travel agencies, etc.) all bluntly offer the "lowest prices"? 

You know what I mean. Every insurance commercial basically says you get the lowest cost. How can they all legally do that? Isn't there one objectively lowest cost?
gpt
Since the question's already been satisfactorily answered on direct, I'll offer some supplemental info that might you might find useful.

As far as the law is concerned, there is a certain class of products that are considered to be exactly equivalent in all situations. Aspirin is the usual example of this; there are many brands of aspirin on the market made by many different companies, but they are all *exactly the same,* by definition.

Which means you cannot truthfully claim that your brand of aspirin is "better." Because it isn't. They're all exactly the same, meaning none is better or worse than any other. It's false — *unlawfully* false, as far as advertising goes — to claim that your aspirin is better than anybody else's.

However, by the exact same rationale, you *can* entirely truthfully and entirely lawfully claim that your brand of aspirin is "best." Because it is. They *all are.* Because they're all exactly the same, meaning there is none better, meaning they're all the best.

There's a critical difference, as far as truth-in-advertising is concerned, because *comparative* and *superlative* claims. If you claim that your product is better than another product — or even just that it's "better" all by itself, without mentioning better than *what* — that's very hard to support, because you have to be able to demonstrate that somebody else's product is worse than yours by some objective metric. But you're absolutely free to claim that your product is "best," because all that suggests is that there is no product which is *better* than yours … which there isn't, by the exact same rationale.

This same general principle applies to claims of "lower" versus "lowest" prices. If you try to claim your prices are "lower," you have to be able to demonstrate that somebody else's prices are *consistently higher* than yours … while claiming your prices are "lowest" is actually the weaker claim, because all that means is that *nobody's* prices are *consistently higher* than yours.

It seems counterintuitive at first, to be sure. One naturally assumes that "best" is a stronger claim than "better" (or more generally, the superlative is always stronger than the comparative). But in truth, it's the other way around. It's a less specific, less conclusive statement to say your prices are *lowest* than it is to say that they're *lower.*