How to successfully use word of mouth marketing in a B2B set up

In B2B since the stakes are higher referrals are not easy to come by, also clients refer your services or products to other businesses if they themselves have tried, tested and are completely satisfied with your services over a period of time.
So how do you ensure that your customers in both B2C and B2B type of businesses give you referrals?

Tags: B2B marketing, Business to Business Marketing, Contests, marketing strategy, mass communication, Micro Marketing, Public Relation tricks, Referral marketing, referral program, reward programs, Social Media, social media marketing, Sweepstakes, viral marketing, WOMM strategy, Word of mouth Marketing