The answer is at the very bottom of the article and maybe Netflix is already doing it. It mentioned a producer was told his show was renewed not based on the "how many people viewed for at least two minutes" metric that gets reported to ratings publishers, but based on how many people actually watched the entire season.

It isn't this trivial for all media, but I think "watched the entire thing" is a very obvious metric to optimize for when recommending and promoting films and series.