It should come as no surprise that pharmaceutical companies pay doctors for a variety of reasons such as research, lecturing, and teaching. Such payments are justified as these physicians tend to be in demand as experts and their expertise is valued. They can't be expected to do this work pro bono – their time is valuable. However, such payments are viewed with great suspicion. Industry critics are quick to charge that what companies are really doing is currying favor with doctors so that they will write more prescriptions for their drugs. This type of "manipulation" is believed to be a conflict-of-interest.