Just be sure to pick a good list, and mail out to these people with an offer that is worth while. Once you can do that, you'll stand a chance of making a lot of money in your business. If you've got a mailing list of at least a thousand mailing list names or more, you're sitting on a gold mine. All it takes is for you to get the word out that you've got a mailing list for rent, at a competitive price, and you should be home free!
First of all, you've got to have a bonafide list of customers - a list of names of people that have responded to an ad or bought from you. You can accumulate such a list simply by noting on 3 by 5 index cards - the names and mailing list addresses of each person sending you something in the mail. If it's in response to an ad you've ran, not that on your file card with the date you received the response.
If it's an order for something you're selling, note that on your file card with the date, and dollar figure relative to what they bought from you. If it's just an incoming offer for something they're selling, note the date and mailing list what they're selling on your index card. Keep your cards filed by zip code, and in alphabetical order within the zip code numbers.