With drop shipping, you’re effectively partnering with a manufacturer or wholesaler to sell their products. This way, you don’t pay upfront costs to buy inventory, aren’t sitting on unsold items taking up expensive warehouse space, and don’t have to deal with shipping the products yourself. You simply create your site, fill it with drop shippable products, and drive in customers, with almost everything else done for you.
If you have an eye for design and some experience of creating websites, then you could offer your services as a freelance web designer. You will need to create your own stylish website, and have a few other projects that you can show potential clients to demonstrate your skills. You will also need to initially spend time emailing businesses to promote your services and find work.
Outbrain is not necessarily the network of choice, it was just an example. As for tracking the ROI usually you'll want to track campaigns in Google analytics and track clicks on affiliate links as event and average value/email or you'll want to duplicate the post and run paid traffic to the duplicate so you know exactly what the conversions are as you can put them in separate email lists etc too.
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.