Holy cow, I wrote a book!
Many years ago, my manager told me about a recruiting trip he made.
In response to a large number of job applications submitted from
a city where a major competing software company had its offices,
a small group of Microsofties travelled to that city to interview
those applicants and hold a mini-job fair, so that other interested
parties could also show up and interview for positions.
When the company learned that Microsoft was coming
to interview people,
they called an emergency meeting which all their top
programmers were required to attend,
timing it to coincide with the job fair.
The theory must have been
that if their top programmers are at the emergency meeting,
then they can't go to the job fair.
Well, except that the plan backfired.
Sure, all the good programmers didn't come to the job fair,
but it also told the interviewers which of the applicants
were the good ones:
They were the ones who didn't show up for their interviews!