payment. exchange of goods or services worth $$$

it’s quite a simple definition of what is or is not advertisement. run it through real world examples, it’s trivial to say whether something is or isn’t an advertisement

as with any broad regulation there would be grey areas, continued cat and mouse games with bad actors, etc.

but it is not a remotely insurmountable obstacle to define what is and is not advertisement in relation to free speech

(as an aside it’s really funny to me anyone would consider being paid to say something free speech, but I get it)