Its becoming increasingly common for former employees to join informal groups (also called comeback colleagues, boomerang employees, or alumni). When treated well, former employees can be extremely valuable, providing quality job candidate referrals, partnering opportunities, and rehires. Why would this be classified as an informal group? Can you provide some examples of companies that are doing this and the benefits that are a result of these informal groups? Would you personally consider being part of a group if you left your current employer or would you hire someone that is part of an informal group at another corporation?