This plugin allows you to track which adverts and traffic were responsible for your sales on your affiliate network reports.
It uses the same fields as the Google Analytics URL builder, namely:
Any traffic that arrives at your website containing the parameters above will be tracked on your affiliate network reports if they convert into a sale. This means you can create unique URLs for your Facebook adverts, your Google Adverts, your various email campaigns, the links on your YouTube videos and any source of traffic you have and this plugin will tell you which of those campaigns is converting the traffic for you.
With the limited time you have as an affiliate marketer, this allows you to focus your efforts on the traffic generation techniques which are truly working well for your niche/products.