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It can be both...someone has to publish an rss feed so you could be on either the side of publishing, or the side of displaying.
In order to publish, many people use a blogging system that automaticaly updates a feed when new content is posted.
In order to publish other peoples feeds you need some sort of software on your webserver, a few are described in here:
Mention the biggest benefit of the product/ebook in your first post and provide the affiliate link. In the next post, explain one big benefit. Don't just cut and paste from the merchant site. You have to show your personality. Give your comments, tell us how it helps us to improve our business or whatever. Show screenshots, your results and like. Include the link to the main sales page or order link from each post.