Always disclose your affiliate relationship. Most visitors will probably understand that graphic ad will lead to your getting paid, but if you write a review or use an in-text link as a recommendation, you want your readers to know that may lead to compensation as well. This ensures you retain transparency and trust with your readers, but also, it's required by the FTC's endorsement rules.
Focus on reviewing products and services that fall within your niche. Then, leveraging the rapport you have created with your audience and your stance as an expert, tell your readers why they would benefit from purchasing the product or service you are promoting. Almost anything sold online can be reviewed if there is an affiliate program – you can review physical products, digital software, or even services booked online, like ride sharing or travel resort booking. It is especially effective to compare this product to others in the same category. Most importantly, make sure you are generating detailed, articulate content to improve conversions.
Another way to find this information is to do a simple Google search. For example, one could place the following phrase into Google Search: “(product name) + affiliate program”. (Replace “product name” with the name of the product you are promoting.) There is an interesting chrome addon called Affilitizer is available which makes this process easy.
As search engines have become more prominent, some affiliate marketers have shifted from sending e-mail spam to creating automatically generated web pages that often contain product data feeds provided by merchants. The goal of such web pages is to manipulate the relevancy or prominence of resources indexed by a search engine, also known as spamdexing. Each page can be targeted to a different niche market through the use of specific keywords, with the result being a skewed form of search engine optimization.