The term Outliers in revenue testing refers to customers that spend far more than the average consumer. This is a problem for the revenue model because it infers the distribution of revenue from previous data, and can lead to skewed results. You can mitigate the potential for outliers to skew results by ignoring outlier data. This will remove the top 0.1% of spenders from the sample size to prevent the data from outliers interfering with the statistical analysis of an experience.