I'd like to make a proposal how we ordinary users can also benefit from that adventure called SO careers.
Make a form for users to propose potential employers to sign-up on careers. if they do, users get some payoff from their new membership.
Looks like SO urgently needs a critical mass of employers. For now it's not very interesting for users hoping for a job offer, so some other way to benefit from it would be nice.
Alternatively, you drop the signup fee in case this user has brought some employer onboard.