In tough economic times people rely more on people they trust before they spend money on anything. If a friend, or several friends, had a good experience with something they are thinking about buying, then they are more likely to buy that item. Referrals make selling easier, in any economic climate. 
   When the phone rings, it is very easy to ask, "By the way, how did you happen to call us?" From a "proper English" perspective, this question is absolutely NOT grammatically correct. However, it is a very friendly way to ask, "Who referred you to us?"
   The answer to this question is critical. Most of the time you will hear: I saw your trucks; XXX referred me to you, or Internet search/"Yellow Pages"-type directory. When you are advertising in the media or a newsletter/postcard/letter went out, you often hear, "I got your newsletter, etc." as the answer to the question. Whatever the answer-track your results. Just put a hash mark on a piece of paper next to the reasons why someone might call. At the end of the week, tally the results. You'll know why people are calling you.
   Finding out where new clients find out about you is important. You want to keep doing the marketing and advertising activities that are working and don't repeat those that aren't working. 
   Of the standard answers, instead of going to the to a "Yellow Pages"-type directory, people are starting to do Web searches prior to calling your company. Various "Yellow Pages"-type directories are now on the Internet in various forms. Make sure that when someone searches something like, "Emergency Plumbing in Denver," for example, that your company name comes up in the first few listings if you offer a relevant service. If not, get a search engine optimization expert to help you increase your visibility on the Internet. 
   In addition, many times when you are using other advertising media (radio, television, etc.) your potential clients will hear the advertisement and go to the Internet to check your company out. It is critical to include a web address in your advertising whenever feasible. And, definitely put it on your trucks. 
   "I saw your truck." This is the reason that your field employees must drive courteously and have clean trucks. You don't want to make a negative impression because of poor driving or have someone notice a dirty truck. You don't want someone to think "I'll never use that company because if their work is as dirty as that truck..." 
   We are the only ones who constantly think about plumbing or HVAC. The reality is that the only time a client or potential client notices us is when they have a need. Otherwise our business is out of their thought process. So, they might notice a truck if they have a need. And, you want them to notice a clean truck so a positive impression is made. Or, they might remember seeing your truck in a neighbor's driveway and ask the neighbor about it.
   Once the need is created, then the potential client usually asks a friend, neighbor, or relative for recommendations. You want to be in that remembrance.
   So, what do you do?
   Create referral and reminder programs. Decide whether you want to be subtle with the programs or openly encourage people to refer their friends and associates to you. A subtle program just "surprises" people with a gift certificate, flowers, a thank you note, an Internet shopping spree, or something else. You make the gesture as a thank you with no expectation or request in return. 
   An overt, open referral program is a conscious effort on your part to tell all clients that you have a referral program, what that program is, and what they can expect if they participate in the program. Some clients will choose to participate, others won't. 
   Announcements for the programs can be as simple as information on the back of a business card. Technicians can point the information out while they are on service calls. It might be included as a flyer with your service tickets. You could announce it in a newsletter or a special mailing to your clients. 
   Referral programs don't have to be complicated. They just have to be consistent. That means if it is verbal, the salesperson mentions it at the end of every job. The office personnel need to know about it so that if a client calls they can explain it to that person. In addition, give everyone in your company the same opportunity to earn a referral fee as your clients. They'll start referring clients to the company too.