Whatever products or services you advertise on your site should make sense for your niche and audience. When you try to sell products or services that will undeniably resonate with your audience, whether they are blog readers or your social media following, they will feel engaged and intrigued. When you try to sell products or services that don’t relate to them or make sense for their lives, they will immediately sense they are being “sold to,” and will become less interested in you and what you have to offer.
Let’s say you have a promotions page where you’re promoting a product via affiliate links. If you currently get 5,000 visits/month at a 2% conversion rate, you have 100 referrals. To get to 200 referrals, you can either focus on getting 5,000 more visitors, or simply increasing the conversion rate to 4%. Which sounds easier? Instead of spending months on blogging, SEO, and social media marketing to get more traffic, you just have to increase the conversion rate by 2%. This can include landing page optimization, testing your calls-to-action, and having a conversion rate optimization strategy in place. By testing and optimizing your site, you’ll get far better results with much less effort. 
In 1994, Tobin launched a beta version of PC Flowers & Gifts on the Internet in cooperation with IBM, who owned half of Prodigy.[5] By 1995 PC Flowers & Gifts had launched a commercial version of the website and had 2,600 affiliate marketing partners on the World Wide Web. Tobin applied for a patent on tracking and affiliate marketing on January 22, 1996, and was issued U.S. Patent number 6,141,666 on Oct 31, 2000. Tobin also received Japanese Patent number 4021941 on Oct 5, 2007, and U.S. Patent number 7,505,913 on Mar 17, 2009, for affiliate marketing and tracking.[6] In July 1998 PC Flowers and Gifts merged with Fingerhut and Federated Department Stores.[7]
I personally prefer to do it that way--you can create a more convincing review that's more likely to make sales. It's not always possible or practical, though; for example, would you break up with your significant other just to test a product for getting your ex back? ;-) In cases like that, or if the product is expensive, it's usually best just to use the vendor's affiliate resources instead.
Will my target audience realistically spend this amount for the product? Again, your reputation is on the line here. Is the product you are thinking of promoting priced reasonably for your audience? When I was writing my ebook, I was stuck on pricing. I asked around for opinions. A number of people suggested I price my ebook at $47! Their idea was to price according to value, not size. In my mind that was crazy. My network was composed of a lot of stay-at-home bloggers, and my collective audience was comprised mostly of people without a whole lot of disposable income. There was no way anyone was going to pay $47 for my 30-page ebook.

An elegantly straightforward process, affiliate marketing via reviews, blogs, social media, and other platforms is a new frontier in marketing that’s just waiting to be utilized. Follow the tips included in this article, and you’ll be able to engage your audience, convert passive readers into active consumers, and enhance your paycheck one click at a time.

You can sell affiliate stuff if you did not use the stuff but a high, high, high, really high level of clarity is required to do this. Most bloggers lack this clarity. I recall Tony Robbins selling/being an affiliate for a $25K coaching class. Never took it. Never sat in it. But the guy made millions. He had full clarity in selling without seeing. So he rocked out the selling.
Also known as a publisher, the affiliate can be either an individual or a company that markets the seller’s product in an appealing way to potential consumers. In other words, the affiliate promotes the product to persuade consumers that it is valuable or beneficial to them and convince them to purchase the product. If the consumer does end up buying the product, the affiliate receives a portion of the revenue made.

To make money from affiliate marketing, you need to ascertain that the product has a high demand. No matter how much efforts you make, you might make little or no sales, it totally depends on the demand of the product. You need to know if it is what your audience really needs. If you manage to get a reasonable amount of traffic on your site, then you can run a small online survey to get input from visitors.

In 2006, the most active sectors for affiliate marketing were the adult gambling, retail industries and file-sharing services.[16]:149–150 The three sectors expected to experience the greatest growth are the mobile phone, finance, and travel sectors.[16] Soon after these sectors came the entertainment (particularly gaming) and Internet-related services (particularly broadband) sectors. Also several of the affiliate solution providers expect to see increased interest from business-to-business marketers and advertisers in using affiliate marketing as part of their mix.[16]:149–150

SEO: getting consistent traffic by writing AWESOME content about your keywords (there’s a phrase “length is strength” in SEO and this paid off big time for me). Maybe you’re doing videos or an eCourse, but I found blog posts WAY easier to update which means less maintenance. The biggest factor by FAR was the time I spent meticulously creating my tutorials… which eventually resulted in a sudden 3x increase in SEO traffic