Employers seek reliable means for keeping their former key employees from interfering with their customer relationships. Restrictive covenants have long played a role in employment law to achieve that goal. For more than a century, New Jersey courts have considered contractual restraints against post-employment competition. See, Mandeville v. Harman, 42 N.J. Eq. 185, 189-190 (Ch. 1886) (holding a non-compete agreement is valid if it is reasonable, provides fair protection to the employer, and does not interfere with the interests of the public).