I heard of (large) brand advertisers where marketing managers bought fraudulent clicks on their own campaigns to "guarantee" success of these campaigns, for internal politics/career reasons. These advertisers probably like it the way it is, and keep their offline marketing colleagues in the dark.
I founded a startup creating an innovative media for mobile that, while probably not "immune" to fraud, had very little space for, and provided accurate and real measurements on engagement and content exposure.
While trying to sell this, I heard multiple advertisers say that they only buy TV ads because it would look "weird" with their hierarchy if the company is not on prime time TV, despite knowing that TV ads are hardly profitable and nearly impossible to measure. The same thing goes for billboards on roads with heavy traffic in the capital.
