At the PR party that was 2000, giddy talk of huge salary increases turned some industry pros into career butterflies, flitting from one job to another. A PricewaterhouseCoopers survey at the time found PR people to be the most footloose and fickle professionals in America.

Employers bemoaned the feeding frenzy and yet knew they had to fight for the talent, while many employees made good while they could, advancing rapidly through the ranks pocketing bountiful stock options and ...