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.
Upwork: This website offers a great marketplace for selling just about any professional service. You don't need a merchant account, website of your own or anything else for that matter. All you need to do is be able to provide a high-quality service at a reasonable price. But be informed, you will have to compete with many others that are constantly bidding on open jobs.
The problem with affiliate marketing, like many other home business options, are the so-called gurus and get-rich-quick programs that suggest affiliate marketing can be done fast and with little effort. Odds are you've read claims of affiliate marketing programs that say you can make hundreds of thousands of dollars a month doing almost nothing ("Three clicks to rich!"). Or, they suggest you can set up your affiliate site, and then forget it, except to check your bank deposits.