If services like zubka catch on, this would be a good way to supplement ones income.

Zubka is a UK company founded in 2006 by two individuals – David Shieldhouse and Armando Ruffini.
Unlike online job boards, Zubka is the first recruitment site aimed at the Referrer. Zubka is a platform where financially motivated referrers introduce their friends and colleagues to great jobs in return for a fee.
Zubka charges significantly less than traditional recruitment firms and gives 80 per cent of all recruitment fees it earns to the Referrer.

Of course, this has the potential to be quite disruptive so one would have to tread carefully.