If you’d like to dramatically increase the number of new customer referrals you get you may want to consider implementing a formal community relations program.
One way to start would be to find a person on your staff that is personable and trustworthy and ask them if they are interested taking the lead in a new initiative you are considering. I would suggest you not position this as a promotion but as an interesting new job related task that will let them get out of the store for a few hours each week. The idea would be to have this person get out for a few hours each week during slow times. I prefer a pharmacy technician wearing some other pharmacy related attire. This truly sets them apart as they visit with others outside your store.