I briefly worked as a contractor for one of the largest ad networks in the world and we outsourced 20K ad review jobs to South Asia over 3 year period. But then

I briefly worked as a contractor for one of the largest ad networks in the world and we outsourced 20K ad review jobs to South Asia over 3 year period. But then came advancement in machine learning and now you only needed a few people to review ads after the adversary networks flagged them.