6. Keeping lists it is expected to use the lists over and over again, they require con tinual care. A list, once compiled, never stays put. A good mailing list is the product of a, constant evolution. People move away, or die, or change their occupations and the mailing list must be revised or scrapped. The rate of depreciation to which a particular list is subject is determined naturally by the nature of the list. A list of farmers who own their own farms may not vary one per cent a year. At the other extreme, a list of salesmen of cheap specialties may have to be revised every month.
One man's "mailing-list creed" reads as follows : "Every possible customer who is not on my list repre sents a leak in my future profits: every man on my list who is not a possible customer represents a leak in present expenses." Constant revising and refining is expensive, but habitual neglect is more expensive.
A local merchant has, in the new editions of local directories, a fairly dependable source from which to revise his list. A national advertiser, however, having on his lists names scattered over small towns and rural districts, may not always find directories avail able. In such a case, perhaps the best method of checking is to send a copy of the list for each town to the postmaster with the request that he cross off the names of all who have left the town. If the post master is tactfully approached he may usually be in duced to perform this service, but the law forbids his adding new names to the list.
7. Filing the mailing necessity of fil ing cards for mailing lists is patent when we consider the frequency of corrections, of removals, of additions, and of new classifications, especially those new classi fications necessary when a prospect has been appealed to or when he has responded to the mail campaign. A certain national concern divides its cards into fifteen distinct classes. Its first three classifications—manu facturers, wholesalers and retailers—are filed together alphabetically, the three classes being distinguished by metallic index tabs. Using cards of different colors is another method of subdividing a file and may be used in co-ordination with the index tabs. The practice of using a single subdivided file is especially commendable where all cards are periodically checked from directories, rating books, or other alphabetical sources; but it is always commendable in that it saves time in searching for a card. The use of several files usually necessitates a great deal of extra work in duplicating cards for crossfiling.'
8. Sales by components of any mail selling campaign are usually a series of letters, often with appropriate inclosures. A single letter does not make a campaign. There must be a suitable follow up or the initial effort is largely wasted.
Whether the letters should be composed for climac tic effect, or whether the strongest appeal should be made in the first letter, is an important problem in planning the series. A cardinal principle in direct mail advertising, however, is that each mailing should be sufficient in itself to convince the prospect and in duce him to act without awaiting subsequent mailings. Even where the climactic plan is not followed, the time element in the follow-ups' deserves attention. The old rule that follow-ups should be sent ten days apart is greater in simplicity than in sales value. In timing follow-ups, importance again attaches to the class of prospects appealed to. A business man answers letters the day they arrive: the farmer or laborer ordinarily is not so prompt.
9. Raking the an expensive booklet is used to describe the goods, it is not advisable to send out the booklet promiscuously to a large list. Instead, a strong appeal should be sent out inviting all inter ested in securing the booklet to mail an inclosed card. Some companies having only inexpensive booklets have found by investigation that tho more replies come when stamped envelops are inclosed, the increase of returns may not warrant the additional expense.
Again, to arouse interest in a proposition a series of "mailing pieces" may be sent to a list of names. The mailing pieces consist of cards or circulars de signed in striking and elaborate style, each presenting one definite point about the product or its use. In each of them a drive is made for a reply from the prospect. When the reply comes, the mailing of the pieces is of course discontinued. At this point the expensive catalog is sent, or the salesman makes a call.
10. The trial campaign.—The list compiled, the letters prepared, and all details of posting decided, it may prove profitable to test the campaign on a repre sentative group of prospects before driving forward on a large scale. An advertiser having a list of, say, 20,000 names may take the first 500 in alphabetical order, and mail his letters to them, keeping careful records of the returns. He may be reasonably certain that his percentage of replies will be about the same from the whole 20,000 as they were from the first 500.