Don't be penny wise and pound foolish. When budget allows, use BusinessWire and Internet News Bureau or another distribution service. Each service has its own way of presenting your story. It's worth the extra money to have another shot at being noticed. Your results go up incrementally when your list is up to date and your spelling is correct.
Editors are busy people.
Decide how you will explain your story in 30 seconds or less before you call. I once pitched a story about three women who had been on welfare and were now each the owners of successful companies. You just can't expect to have an editor who gets 100 PR calls a day to listen to a long-winded pitch. Because you are so close to your business it is hard to maintain journalistic perspective. The world at large is not going to find your triumphs and struggles captivating.