A content engine receives a content request from a client, generates a result including one of a content-providing value and a redirection value in response to the content request, and selectively provides, to the client, one of (i) content when the result includes the content-providing value, and (ii) a redirection message when the result includes the redirection value, the redirection message including an extended domain name having a client identifier which identifies the client. The result can be used by a content router or content engine in deciding whether to provide content or a redirection. The decision to selectively provide can be based on client proximity to the content engines, past redirections, content size and type, content engine capacity, content availability and other factors.