They add zero to the game but being a billboard advertising the character in question?
How about, when the character is being clicked, instead a transparent 2d sheet pops up. it could contain recruitment adds from the owner, or paid ones from corporations within the structure, or market oders, contracts, propaganda, etc?
The character could, instead of being an image the owner, be a specifically created character working as "Customer Service"esque, fancy and irrelevant addition.
Your idea needs more options within it. i suggest adding the above, and more, to your initial post. Unless the heat affects me too much (35+ and no AC makes it happen that i lose context unawarely), it seems to me that there’s need for these characters beyond being gigantic attention whoring faximile of possibly ugly looking characters.
PS: no offense intended.