Review: Since Refersion charges based on the quantity of affiliate sales processed in a given month, I recommend them for medium/higher ticket item stores, or stores with an average checkout of $30-$60 or higher. At that level, their fee structure becomes very attractive because you're only paying incrementally for sales, and not for traffic, whereas many other apps charge based on the number of visits regardless of where they originate from. Whereas if you're a high volume low ticket store, you might prefer paying for traffic and getting unlimited sales.
The online lead generation is a multi-billion dollar industry. Done right it can be far more profitable than many imagine. Everyone that I know that is in the business and knows what they are doing, for the most part, does 6-7 figures. While that's a huge range, much comes to one's ability to scale and effectively build / manage the infrastructure needed to scale.