My solution is similar to jbenton, but I assume the quotas might be different for each salesman/woman.
I would have a second table of three columns (D to F). First column (Personnel) with the names, second (Quota) with the assigned quotas for each one, third column with this formula (cell F2):
=IF(SumIf(Sales[Personnel],D2,Sales[Sold]))E2,"Below Quota","Great Job!!").