Market intelligence will denote some results as market outliers if they have characteristics that fall outside of the market norms. The most common reason a result is marked as an outlier is that it has sales that are either much higher or much lower than that of the average. You can see why each outlier was marked as such by hovering over the red "!" on the left side of the result (see below)
You can still include these results in your analysis by checking the box on the left side of the result and then clicking the 'update analysis' button.