Proving damages is a necessary prerequisite of being awarded damages, yet doing so can be exceedingly difficult. If damages are awarded, they are typically measured by either the plaintiff's lost profits, or defendant's profits. In the case of plaintiff's lost profits, proof issues are particularly tricky since many factors may result in a decline in plaintiff's profits at any given time. A market survey may be useful here to demonstrate loss of reputation which can serve as circumstantial evidence of lost profits. When the award sought is defendant's profits, all that plaintiff must prove is the amount of defendant's gross sales. Then the burden shifts to the defendant to prove reasonable deductions from those sales.