Sometimes companies will work by asking people for referrals for their job opportunities. This means they might ask existing members of staff if they know anyone who might be able to fill vacancies, and then these people can be put forward for the role. It can be a very successful way to recruit, as the people who are invited to interview will have come highly recommended.
Recruitment agencies may also operate in this way, asking other job seekers and people they may already have placed in a role whether they can recommend people for their current positions. They may also offer financial incentives, giving people a reason to put those in their network forward. Look out for incentives like this with your recruitment agency, as it could be your chance to help your friends find a good job, and to get a reward for yourself. Recruitment agencies have many good strategies for placing people in the right jobs.