I want to introduce a Pest control business to companies who would want to make use of the services we offer

Hello, Sandra!

I moved your question to its own thread that you had posted as an answer/response to someone else's question so that it would get noticed more. It's best not to be piggybacking questions here like you might in a chat room, because this place doesn't work the same way that a chat room does.

Do you already have business cards made up for your business? You could also have a nice flyer made that has some color graphics on it with a description of your business, services and prices. You could then cold-call (go to them in person) with your information. I think that sort of direct approach, without being pushy and then leaving your information with them, especially for you with a small business, would be the way to go. Letters are okay, but you would probably get more results by speaking with managers/owners directly. I think that companies would appreciate the personal touch.

I will agree, many companies may already have someone, others not paying because of prices. So for some accounts it will be a routine follow-up in person or on the phone to let them know you want the business. But often a discout or special service will draw some business

In support of the above, I agree. You have to sell yourself. If they already have someone else, then you need to be competitive in some way by showing them that what you have to offer is going to be better in some way. You've got to catch their attention and draw their interest in some way - stand out from the rest of the competition.