Nothing goes further than a personal recommendation or testimonial and here's why:
1) It comes from experience. This customer has seen how you operate and likes what they saw. They can share firsthand knowledge about you and your reputation as a Realtor.
2) It is unsolicited. They are sharing this information with anyone interested in finding a Realtor in your area. Just like they would give out the name of their favorite restaurant, barber or doctor who has given them good service, they are recommending you as the best to work with in buying or selling a home.
3) Your prospective buyers/sellers can identify with them. They share something in common, whether they are relocating from another area of the country, employed with a large company or a member of the military, or just someone who needs to upgrade or downsize from their current home.
4) It adds a human aspect to your advertising. In other words, your ads aren't just listing all your credentials and achievements, it is explaining why and how you achieved them and it is in the words of someone besides you!
So how do you get good testimonials? You have to ask for them! Although now and then some really nice client will take the time to write you a thank you note, rarely do they write out a recommendation and send it to you for publication. Therefore, get over your shyness and tell your customers that you would really appreciate a short paragraph or two that you can share with prospective clients about their experience working with you. They will be so excited that you asked them and will usually respond very quickly, especially if you send them a sheet of paper and a return self-addressed stamped envelope to use. Bob and I did this and received more than we had space to post on the Testimonials page of his website. Working with military families who have received orders to pcs to Fort Benning, Georgia, we know that they rely on the recommendations of other Military personnel when choosing a Realtor.