In Raiser's Edge you can select Random sampling to calculate a specific number of records you want to use in a query. For example, your constituent query contains 600 records. Your budget will only allow for a mailing to 300 constituents. In the No. of records to include field, enter 300. Your query results still display 600 constituent records, but only 300 records receive the appeal when you use the query in Mail or Export. This functionality is not available in CRM.