The value of information or entertainment might not seem relevant. Though the spreading of information or entertainment might.
It's all personal. A datamining company like Google holds value in it by presenting you ads that are relevant to your interest. Considering that Google holds little power in the fediverse, the value does not come from there.
The value of spreading information or entertainment is subjective, though sometimes quantifiable in that people might buy a product because of a post. I know I bought a few games thanks to lemmy.
I short: not usually financially. Maybe mental value.