(not too satisfied with this terminology. I used to call this "parasitizing on popularity", but a parasite causes harm to the host, whereas the sort of interaction I'm describing need not harm the more popular person.)
one of the things i've noticed is that i find people by looking for discussions of more famous people. e.g. i might find some random person's blog by searching for keith frankish, or i might find someone's solutions to exercises in sutton and barto. i also remember one time searching for japanese book reviews of daniel dennett books. and sometimes, if that discussion is good, i will get curious about what else this person has done. In other words, these random people can parasitize on these famous people's popularity. i think this is a good thing, in a way. basically, if your discussion is good, you are adding value, and you're adding value by working on something that other people are already curious about.
there seem to be less-virtuous nearby actions, like just spamming a popular person's blog comments.
Related idea: building off what a more famous person has produced, in the hopes of getting feedback from them/getting them to boost your work .
entire genres of output can be based on this idea, e.g. video game walkthroughs (parasitizing on the popularity of the game), solutions manuals, critical analysis (of books, films, animes).
here is a good example of this: i saw that someone had inserted a timestamped link to one of Jonathan Blow's talks as a citation, and reasoned that whoever did this must be plausibly interesting. It turns out that this person indeed does have some interesting things on their website: http://hamishtodd1.github.io/
so there's two sides to using this idea: (1) using it to find interesting people; and (2) using it to get attention/as a way for others to discover you.