Nothing about you decided it. Everybody looking at that space right now is being shown the same advertisement, and which one that is comes from the clock: the live campaigns for a space take turns, about every 90 seconds, in a fixed order.

That is the entire mechanism. There is no profile of you here for an advertiser to buy, because this site does not build one. Nothing you follow, read, click, or type is used to choose an advertisement, and there is no column in the database that could hold it if somebody tried.

That their advertisement was drawn, and that somebody clicked it. Not who, not from where, and not what else that person was doing.

Clicking goes through this site rather than straight out, so the click can be counted, and the advertiser is told only that the visit came from kek.social and not which page you were reading when you clicked. Nothing loads from anybody else's server until you click: the picture in an advertisement is stored here, like everything else on the page.

The paid tier turns advertisements off on your own pages. It changes nothing for anybody else, and it buys nothing else anybody can see.