Why the hidden job market just might be one big misunderstanding. This is a guest post by Lavie Margolin. If you’d also like to guest post here on JobMob, follow these guest post guidelines. How many corporations and government institutions do you know of that do not post their jobs publicly? True or false: 80% of openings are never advertised Consider any organization with more than 300 workers. Go to the website of a Fortune 500 company and find the job listings section. You will likely see pages and pages of job vacancies.