Affiliate agreements can be entered into by any type of business, from sole proprietor to corporation. Affiliating with another company is a good way to promote your business and make more money by joining with someone who has a proven track record and a larger customer base. But before you join an affiliate program of any kind, consider these questions (from Leslie Truex, Home Business expert).
The other type of Amazon affiliate link I use is when I’m mentioning a product in passing and/or a new product is announced. For example, when Nikon announced the Nikon D300s we immediately posted about the news because it was a notable and anticipated camera announcement. The camera was not yet available in stores and we were not able to get a review sample yet – but it was available for Pre-Order on Amazon so we linked to it.
Upwork: This website offers a great marketplace for selling just about any professional service. You don't need a merchant account, website of your own or anything else for that matter. All you need to do is be able to provide a high-quality service at a reasonable price. But be informed, you will have to compete with many others that are constantly bidding on open jobs.
Freelancing is the next best thing to being paid more for your full-time work, because professional work always pays more than unskilled. To find opportunities, let former colleagues or other personal connections that you’re available for freelance gigs. (Here are some ideas on how LinkedIn could be useful for that.) Or, post on marketplaces particular to your field. For instance, Mediabistro, a journalism site, allows freelancers to post profiles of their experience and services. Though these are more up to chance, designers can bid on jobs at 99Designs.com or submit a design at Threadless, to see if it will be crowdfunded. Elance-Odesk also lists many freelance opportunities, and you can also post your own services on Fiverr, although some freelancers say these services create a race to the bottom on fees and so are not very lucrative. If you're new to freelancing, here's how to set your rates, and here's how to negotiate raises with clients.