In 2008 the state of New York passed a law asserting sales tax jurisdiction over Amazon.com sales to New York residents. New York was aware of Amazon affiliates operating within the state. In Quill Corp. v. North Dakota, the US Supreme Court ruled that the presence of independent sales representatives may allow a state to require sales tax collections. New York determined that affiliates are such independent sales representatives. The New York law became known as "Amazon's law" and was quickly emulated by other states. While that was the first time states successfully addressed the internet tax gap, since 2018 states have been free to assert sales tax jurisdiction over sales to their residents regardless of the presence of retailer affiliates.
Despite its older origins, email marketing is still a viable source of affiliate marketing income. Some affiliates have email lists they can use to promote the seller’s products. Others may leverage email newsletters that include hyperlinks to products, earning a commission after the consumer purchases the product. Another method is for the affiliate to build an email list over time. They use their various campaigns to collect emails en masse, then send out emails regarding the products they are promoting.
Many voucher code web sites use a click-to-reveal format, which requires the web site user to click to reveal the voucher code. The action of clicking places the cookie on the website visitor's computer. In the United Kingdom, the IAB Affiliate Council under chair Matt Bailey announced regulations that stated that "Affiliates must not use a mechanism whereby users are encouraged to click to interact with content where it is unclear or confusing what the outcome will be."