Cost per action/sale methods require that referred visitors do more than visit the advertiser's website before the affiliate receives a commission. The advertiser must convert that visitor first. It is in the best interest of the affiliate to send the most closely targeted traffic to the advertiser as possible to increase the chance of a conversion. The risk and loss are shared between the affiliate and the advertiser.
Companies like Uber and Lyft offer a great opportunity to make some quick cash. You'll need a clean driving record, a fairly new car and the authorization to work wherever it is that you live. If you have all of those things, you can work when it's feasible for you, whether that's in the middle of the day during rush hour, or in the wee hours of the night on a weekend. The choice is yours.
I concluded that having read a product review, people felt more informed to make a purchasing decision. As a result, if they did click a link after reading the review they were more likely to buy the product. Those clicking on the top link seemed to be more in a ‘surfing’ mode. They clicked on the link less because they wanted to buy it but more out of interest to learn more. Some bought the product and some bought other products once they were ‘in the door’ at Amazon.