When the payment is “recurring,” it doesn’t just occur once, but repeatedly as long as your commissioned user is still a paying customer. Recurring income programs pay their commissions monthly because of the customer retention rate. Most recurring programs are software as a service (SaaS) advertisers whose platforms require a monthly subscription.
The traffic was relevant. But they weren't getting more fields or more leads for people who just wanted to go view or test drive a car. So they created Crazy Egg to see how people engaged on someone's website. They put the code on there and it shows you if they are scrolling down, not scrolling, were they clicking, were they not clicking. They discovered that with many websites, visitors don't scroll pass the fold.
Wirecutter's affiliate program might make you doubt the legitimacy of Wirecutter's recommendations -- but, in fact, it's quite the opposite. Wirecutter only makes commission when a reader purchases a product from an affiliate retailer and doesn't return the product. Wirecutter, then, has no incentive to promote inferior products -- if they did, they'd make less money and turn away readers.