In my opinion, its not how much advertising does or does not cost which makes it good. Its whether or not its hitting enough people and are they targeted for interests such as SFI, or building your own business. Before I pay for advertising, i always ask teh vendor beforehand who is getting my ads. You want to get a list of about 5-6 questions focusing on if they are targeting your demographic or not. Sometimes the free sites do this for you.