Apparently the reason they're loaded separately in the first place is fraud detection. Bundling it into the page provides no easy way of independently verifying impressions.
such as site X has sent us 1000 users and 10 of those have signed up so we pay them for these 10 signups/purchases whatever
interestingly amazon are the leaders here...
People keep trying to start paid-for publishing networks. Maybe Netflix will start reaching out to prominent youtubers and take them on as series? Maybe Reddit should find a way of giving "gold" to the link target of a post as well as just commentators?