I have never worked in a company directly funded through advertising dollars, either. But I have worked in companies that make software for the marketing people

I have never worked in a company directly funded through advertising dollars, either. But I have worked in companies that make software for the marketing people to bother their advertising-found customers with, companies that make software that ensures the uptime of the attention-grabbing platform... These are first-derivative bullshit jobs. My job provides an useful service in that it enables other people to do their bullshit jobs. Those jobs do not need to exist, and if they didn't, my job would not need to exist, either.