Clickbank, huh... now that's a name I haven't heard in a while! I remember messing around with them back in 2011 when I was a newbie. Never did make any money with them, haha, but I've seen plenty of people who have! I've just never been any good at pushing the weight loss stuff, which I'm pretty sure is where most people make their money with Clickbank.
Amazon offers a service called Fulfillment by Amazon (FBA), which can be extremely useful for arbitrage sellers, or others selling their own products. If you opt for FBA, Amazon will store, pick, pack and deliver your products. That means you can scale your arbitrage business quickly as you don’t have to store products in your own home or waste time with postage.
Now most affiliate programs have strict terms and conditions on how the lead is to be generated. There are also certain methods that are outright banned, such as installing adware or spyware that redirect all search queries for a product to an affiliate's page. Some affiliate marketing programs go as far as to lay out how a product or service is to be discussed in the content before an affiliate link can be validated.
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.
Clickbank is a market platform for vendors (product creators) to sell their digital products. Such products could range from ebooks, downloadable resources/programs or online membership sites. On the flip side, it’s also a place that widely attracts affiliate marketers to help these creators sell their products, essentially giving them a source of free publicity and advertising in exchange for a commission fee on every sale.