You might want to have your coaches promote your business and get credit for the referrals s/he brings in. When registering on the Lead Generation Landing Page, a person can choose the coach that referred them, but often prospective clients will opt not to divulge this data.
There's a way your coaches can send off URLs to prospective clients which will automatically assign the lead and the referral to the coach.
In order for each coach to get their own personal Lead Generation Landing Page link, go to the coach record and click on the "My Lead Gen Link" button on the right rail. This will open up a landing page that will automatically include that coach as the referral source.