The other day I received an email with the subject line "[Name of referrer] gave me your name as a referral for web and graphic design." The referrer's name was someone I knew and respected, so I opened the email, even though I had absolutely no interest in talking to anyone about my website.
Unfortunately, that was the only reference to the referrer in the whole email. The email focused entirely on "who we are," "what we do," "who we work with," etc. At no point did the sender explain how he helped my colleague or demonstrate why I should call him. In short, he missed a big opportunity to leverage his referral.