Employers (and recruiters) have an increasingly number of good Internet resources at their disposal to scope out and learn more about potential employees using publicly available information that these job searchers are either putting out there themselves or that are available due to their connections and friends on various social networks.
In the old days before [...]

A good reference might not get you a job on its own but it will certainly help to get you closer to it anyways.
Even better than a good reference can be a referral from a former manager (presumably your current manager won’t refer you to another company!) and/or colleague.
As a recruiter, one of [...]