Q: If I already have several established websites, how can I get started? Is affiliate marketing business specific? Meaning are there some businesses that would not benefit from this type of advertising program?
I think these will give you some direction. As far as affiliate marketing being business specific, it is to a degree. Most affiliate programs are for B2C (business to consumer) companies, rather than B2B (business to business companies.
The reason being that it’s easier to recruit affiliates for a product or service that is appealing to a wide audience.
However, there are plenty of B2B segments that thrive in affiliate marketing, such as domain registration, Web hosting, ISPs, etc.
It really depends on the focus of your site(s) as to what is available out there.