The National Commercial Detective Association

Last weekend I took a trip to Wabasha, Minnesota. I visited a local antique store and picked up this lovely find for about $8. If these get you curious for a good story there's this site to fill all your old timey gossip needs. Miss Cora Strayer's Private Detective Agency 
Below is a dictation of the Notice on the inside of the cover.

The text on the Notice is pretty hilarious. As to not strain your eyes on the image, I've dictated here for you. It is as follows:

NOTICE

Kindly observe the following rules in the use of these forms:
1. Always use an unprinted envelope in mailing these letters. After sending out the first form furnished, wait a reasonable time for results, and if not forthcoming? Mail letter No. 2 in the same manner. If this letter also fails to produce returns in a reasonable time, send out the last form in the same manner as the others.
2. BE SURE-To mail them from some other post office than the Town in which you reside. If you live in a small place, the best results are usually secured by mailing them from the largest city or town near to the place in which you live. When it is convenient to do so, a good plan is to give the letters to the mail messenger on a train. But at a station distant from your own place of business or residence, for in that way the envelope will not get a post office postmark and the person to whom the letter is addressed will not be able to tell where it was sent from. If you have a typewriter, it is better to fill out the forms in that manner.
If written otherwise, do not use a pencil, but pen and ink and if there is a possibility of your debtor being acquainted with your handwriting, get some friend whom you can trust to do the writing. In this manner, the person addressed is kept mystified as to the origin and it will bother him, for the word "DETECTIVE" is not greatly relished by him, gives him shudders and he will worry over the matter to the extent that he will pay whole or part to ease his mind. If he comes to you with excuses and requests more time to pay, tell him that you have given him all the consideration possible, when he would not listen and that nothing but payment will stop further action and put him right with the Association.
There are times when "patience ceases to be a virtue," and you can not afford to be sympathetic after you once have your debtor scared, which is the time to follow out this System until you have secured what is honestly due you.
PRICE $5.00