Get the Most From Outside Lists

6. Pyramid the quantity on subsequent tests. Increase the quantity of any one list cautiously. If you test 10,000 names with a great deal of success, mail 20,000 names the next time. Assuming the results hold up, then go to 40,000, and pyramid up from there. Resist the temptation to take too many names of any given list based on the results of the initial test.