This is one of your marketing expenses which will not be recouped in just a few mailings or a few years. Buyers equals profit. Once you have buyers on your list and you are providing service and products, they will come back to you and the profits will start coming in. You need a list of names of people to whom you can mail information or who you can telephone. You can rent lists that target the buyers you are trying to reach.
Compiled lists are available.
You can choose different segments of the country, different occupations, different income levels. For instance, if you want to reach all the aerial sprayers in one zip code area, use of compiled lists can pinpoint your potential customers. Sometimes you can also rent lists from comparable types of businesses. You probably can't rent from a direct competitor. You should use a list broker who will make recommendations for lists to rent.