As well as the existing 'nth' and 'random' options, add a 'top' option, so that the first n records returned by the Selection, are chosen. That way, we could, for example, include the first 150 people by donation amount, Attribute value or anything else which we can use to define the order of the results of an Ad-hoc Query. That would be much easier than the current process of having to include many more records than we want and then removing members from the Marketing Effort after activation.