Agency's army of spineless sales people [1] spends a lot of time ass licking many people, one of them happens to love his anus tickled in that manner, then he dumps a bag of money to them, they spend 90% of that money pumping ads, and 10% on development of what's supposed to masquerade as a 'marketing campaign'. Anus-tickle-lover still gets a nice spreadsheet at the end of the month ('Yay, profits!') and they all live happily ever after.
Well, not all. In-house developers crook their spine to the will of their masters and get an occassional team-building event paid for, and outsourced developers get eaten alive in the witch's cabin.
[1] It helps if you're a handsome woman. A fact, sir. No citation needed. Desired even.