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.
Unlike most offline marketing efforts, digital marketing allows marketers to see accurate results in real time. If you've ever put an advert in a newspaper, you'll know how difficult it is to estimate how many people actually flipped to that page and paid attention to your ad. There's no surefire way to know if that ad was responsible for any sales at all.