White label SEO is a term used to refer to the process by which internet marketers outsource SEO services to a third-party.
Internet marketing is a broad field which encompasses lots of different tasks. Customer acquisition, lead generation, branding, and more are all part of digital marketing. SEO is another part of internet marketing, but some agencies prefer to focus in on other areas rather than stretch themselves too thin trying to carry out SEO on top of everything else.
Therefore, they outsource their SEO to specialists like Whitelabelers Ltd
who then handle the SEO for them. The third-party SEO specialist helps to rank the content or website in the SERPs, while the agency takes care of all other marketing tasks and liaises with the clients. It's sold to the client as one complete package.
White label SEO is not to be confused with white hat SEO - another term used in internet marketing to refer to legitimate, low-risk SEO techniques.