Your answer is:
"One simple answer to the question is Geography."
There are two problems with your answer:
1. He isn't asking how to get more people to click on ads, he is asking why our best minds are working on that problem.
2. Geography isn't the answer to people clicking on ads, it just happens to be very important if it's a job ad (according to your experience). There are plenty of ads that aren't for jobs and Geography is not the answer.
It is interesting to hear your findings about job ads, but the context of your post and the summary of the results don't seem to fit.