In regard to Yellow Pages, here in Denver the phone company yellow pages offered marketing figures and stats for you. They compiled the total calls somehow, probably by keeping track of all the phone calls to the numbers listed in a category and even broke up the results into stats for advertisers. They wouldn't show me the names of the companies in the results, but they would show you what sized ads and the placements and what the results were. I thought it was a very good way to gauge what you wanted to do. Sadly Quest has sold the yellow pages division and I'm not sure if the new owners are doing the same program.
In regard to direct mail. Direct mail results can be extremely misleading. ROI return on investment is what it is all about. A 1% or even a 5% response doesn't mean anything, how many of those people became customers really matters and of course there are a million personal variables that cause that ratio to be different for each person in business. I can get a huge response, take the outlandish example of doing a direct mail piece that says call my number and I will give you $20 just for calling. It depends on the results you are after. You can make the phone ring, but are the people on the other end really legitimate potential customers?
There are many factors that affect the outcome of the mailing. The quality of the mailer, the scope of the offer and of course the target you are mailing to.
I have done saturation mailings for another business which can be extremely cheap compared to other methods. If you want to target a geographic area I would be happy to give the step by step methods. You can get a large post card into the hands of every person in a neighborhood, a zip code, a county whatever you want as low as 16 cents per piece, that includes postage! This is a great way to farm a particularly lucrative region. Say you are a roofer and a hail storm blows through a section of town, you could get a postcard into the hands of everybody in that area quickly and cheaply and pick up a bunch of work. Say you are a sprinkler guy and a town near you suddenly passes a water restriction, you could get a post card into everybodys hands in that area about your tune up specials for sprinklers.
The other side of the coin is yes, in the saturation mailings you are using a shot gun approach, hitting many, many people who are not your potential customers, the other way is a very targetted approach such as purchasing a list based on demographics such as income or new homeowners. You might spend more money on this type of mailing. Where as on a saturation mailing you might send out 10,000 pieces ($1600 @ 16 cents apiece) and only get 3 jobs. On a targeted mailing you might only send out 2000 pieces ($1500 @ 75 cents apiece) if you get 5 jobs then you now know which one to do more of.
Keep in mind that your response ratio goes up the more times you repeat the mailing. If you mail 4 times a year to the same neighborhood, each time you do it you will get a better and better response as people start to recognize your name and get comfortable with you. It is the old "Well, his company is always around doing something or sending something to me, they might be worth trying out."
Also you have to test, test, test. Never send out the same piece to everybody on your mailing. Split the list and send out 2 different pieces, see which one got the best response and next time use the one that worked the best and another one and split the list again, keep doing this and you eventually will have a super mailer! This can be applied to your newspaper ads also. In marketing you need to continually test so your money is working smarter and smarter for you.