In the case of cost per mille/click, the publisher is not concerned about whether a visitor is a member of the audience that the advertiser tries to attract and is able to convert because at this point the publisher has already earned his commission. This leaves the greater, and, in case of cost per mille, the full risk and loss (if the visitor cannot be converted) to the advertiser.
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.