Pay-for-performance SEO is a pricing model where clients only pay once the provider has delivered results. For example, a provider might offer to get your website ranking for ‘plumber canberra’ and only charge you when your site ranks on the first page. Many providers even promise specific positions, like spots 1-3, with prices varying according to each position. This SEO model differs from traditional SEO services, where you pay a monthly retainer for ongoing SEO, no matter how rankings change in the short term.
See also: Black hat SEO, Manual penalty
Further reading: Why You Should Avoid Pay-For-Performance SEO Agencies