The violations that the average human has been unknowingly a victim of, courtesy of the advertising industry, are in my estimation so insurmountably numerous that I automatically consider someone working in advertising ontologically evil. More so than, say, someone working on face recognition at Lockheed Martin.
To be clear: creating media for the purposes of spreading an idea is not inherently bad. What's bad is having an industry built around planting ideas in human minds, regardless of the validity or broad utility of those ideas.
And to head off "but then how will people learn about ?" People buy marketing material, coupon books, attend conferences for the things they care about, and if necessary research options when they need something. A market does not need the feature of shoving information about available products and services in everyone's face to function well. And if you're someone who likes seeing ads, great, open up the yellow pages or digital equivalent and look at all the ads you want. How will ad-supported services like mass social-media sites fund themselves? Not my problem, maybe they don't and they shit down. What a shame.