Just like all of the other elements of your marketing plan, website promotion can cost money. Fortunately, what you pay for the exposure is still dimes on the dollar compared to traditional advertising, but it is an expense none the less.
Pay per click search engines are a great idea, although they can get quite expensive if you aren't careful.
The main benefit of using a PPC, is you are getting highly targeted visitors to your website and you only pay when someone visits your site by clicking on that link. Opt in newsletters are basically a service you offer on your website that lets people sign up to read about your valuable information.