Cost per click was more common in the early days of affiliate marketing but has diminished in use over time due to click fraud issues very similar to the click fraud issues modern search engines are facing today. Contextual advertising programs are not considered in the statistic pertaining to the diminished use of cost per click, as it is uncertain if contextual advertising can be considered affiliate marketing.

The debt-to-equity ratio is an indicator of capital structure. A high proportion of debt, reflected in a high debt-to-equity ratio, tends to make a company's earnings, free cash flow, and ultimately the returns to its investors, more risky or volatile. Investors compare a company's debt-to-equity ratio with those of other companies in the same industry, and examine trends in debt-to-equity ratios and free cash flow.

Let’s say you have a promotions page where you’re promoting a product via affiliate links. If you currently get 5,000 visits/month at a 2% conversion rate, you have 100 referrals. To get to 200 referrals, you can either focus on getting 5,000 more visitors, or simply increasing the conversion rate to 4%. Which sounds easier? Instead of spending months building domain authority with blogging and guest posts to get more organic traffic, you just have to increase the conversion rate by 2%. This can include landing page optimization, testing your calls-to-action, and having a conversion rate optimization strategy in place. By testing and optimizing your site, you’ll get far better results with much less effort. 

Some advertisers offer multi-tier programs that distribute commission into a hierarchical referral network of sign-ups and sub-partners. In practical terms, publisher "A" signs up to the program with an advertiser and gets rewarded for the agreed activity conducted by a referred visitor. If publisher "A" attracts publishers "B" and "C" to sign up for the same program using his sign-up code, all future activities performed by publishers "B" and "C" will result in additional commission (at a lower rate) for publisher "A".