Ok... wow I have so much information to give but I will try to be as specific and precise as possible.
First of all, Are people actively looking for services similar to yours? If companies are actually looking for a service like yours, I would recommend using Google Adwords with a direct response website.
If the situation is different, for example you can save people money in a way they wouldn't expect. Which basically means they would not be looking for your services because they don't really know they exist. If this is the case I would use direct mailing, however there is a lot to learn about direct mailing and copy writing to ensure you get a good response.
I would love to give you a free 15 minute consultation over Skype, where I could ask you a few questions, discover more about your situation, and provide you with the best possible advice and action steps possible.
If you would be interested just send me a message.
Visit James Farren's Productivity Blog ProducingProductivit,.com To Double Your Productivity!