You can find affiliate marketing offers on sites like ClickBank, CJ.com and Rakuten LinkShare, amongst many others. Search for the right offer and ensure that you present it to the right audience and don't spam people about it. Do your marketing ethically. If you're looking for more information on effective affiliate marketing, check out Pat Flynn's Smart Passive Income website.
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.
If you have a background in marketing and a passion for a particular niche, then organizing a virtual event may be just up your street. A virtual event could span across a day or longer. Individual live sessions would be run by experts in the field. And conference features would include live question and answer sessions, forums, and plenty of free giveaways. Visitors to the virtual event would pay to attend, so the more effective your promotion of the event the more money you would make.