Since you will be promoting a product or service, you will need a killer sales pitch and website content to get your readers interested in the product, convince them that they cannot live without the product, and to keep them coming back to your website time and time again for more recommendations and your useful content, which will get them clicking on your links once again. Although many affiliate companies only give you money off of the first sale you make from each customer, you have the option of promoting a good range of companies so that you can still make a profit off of your returning customers.
If you cannot write this kind of content of your own, there are many ways to pick up free or paid content to place on your affiliate website. There are many reasons why paying for such articles would be to your advantage. First, you will be able to tell the writer exactly what you want, what product you are trying to sell, and what direction they can go in to keep your readers interested and informed. On the other hand, when you search for free content, you are limited to what is already out there. Secondly, you will own the copyright to this content. That means that no one else can reuse it without your consent. If you opt for free content, you will be sharing that content with an unknown amount of other affiliate websites, plus the original author will be able to place their byline at the bottom of the article which could result in them stealing your traffic.
There are many products that have nice affiliate commission rates for those who know how to pre-sale their product and deliver click through customers who are ready to buy. As long as you choose to promote a product or service that can be very useful to a wide variety of people, then pre-selling your chosen company may not be that hard at all. The key in this situation may likely be getting those customers to your website so that they have a chance to see your recommendations and click on your affiliate links.