This is a letter a friend of mine found in his grandfather's papers. His grandfather was subbed out by by the power company to install the "New" Wiring jobs in a house. If you look at the date at the top of the letter, I believe it was dated 3/2/1916, and I guess they were sending out these letters to everyone that they could in order to get them to wire up their houses. Enjoy
Can't determine if "JPW" wants 2000 or 20,000 copies. Postage back then was .02 for a normal letter, and .01 for a post card. So the advertizing cost for the direct mail was probably between .08 and .12 total.
I suppose they didn't type each letter - more likely they typed it onto a sheet of wax or special carbon copy paper and made a bunch of prints (some systems could produce up to 500 copies from one original I think).
It would be interesting to put those prices into perspective - what did an average worker make per week back then? If he made say $3/week, wiring a house was still quite expensive for him!