Third party customized content based on first party identifer

A system comprising:

• one or more servers;
• and
• one or more memory elements including instructions that when executed cause the one or more servers to perform operations comprising:
• receiving, from a browser that is configured to block third party cookies that are of a different domain than a domain of a publisher page and while the publisher page is presented by the browser at a client device, a request that includes a first encrypted cookie generated as a first party cookie to the publisher page;
• providing, responsive to the received request, a content item including a script that, upon interaction with the content item, causes the browser to execute a navigation request that includes the first encrypted cookie;
• receiving, from the browser, the navigation request including the first encrypted cookie;
• mapping the first encrypted cookie to a server cookie that is a first party cookie to the domain of the one or more servers and a third party cookie to the domain of the publisher page;
• serving content selected using information corresponding to the server cookie in response to receipt of subsequent requests for content that include the first encrypted cookie based on the mapping between the server cookie and the first encrypted cookie.

A non-transitory computer readable medium storing instructions that when executed cause one or more servers to perform operations comprising:

• receiving, from a browser that is configured to block third party cookies that are of a different domain than a domain of a publisher page and while the publisher page is presented by the browser at a client device, a request that includes a first encrypted cookie generated as a first party cookie to the publisher page;
• providing, responsive to the received request, a content item including a script that, upon interaction with the content item, causes the browser to execute a navigation request that includes the first encrypted cookie;
• receiving, from the browser, the navigation request including the first encrypted cookie;
• mapping the first encrypted cookie to a server cookie that is a first party cookie to the domain of the one or more servers and a third party cookie to the domain of the publisher page;
• serving content selected using information corresponding to the server cookie in response to receipt of subsequent requests for content that include the first encrypted cookie based on the mapping between the server cookie and the first encrypted cookie.