DNS 廣告模式

最近有位朋友來談到DNS based 廣告模式。上網查了一下，原來在2011年就有人在研究這種廣告模式。參考下列連結：

http://www.icir.org/christian/publications/2011-foci-dns.pdf

摘要他的模式如下：

Internet Service Providers (ISPs) increasingly try to grow their profit margins by employing “error traffic monetization,” the practice of redirecting customers whose DNS lookups fail to advertisement-oriented Web servers. －－－ One monetization vendor, Paxfire, transgresses the error-based model and also reroutes all user search queries to Bing, Yahoo, and (sometimes) Google via proxy servers controlled or provided by Paxfire.

Error traffic monetization solutions leverage the con- text provided by ISP customer traffic in order to rewrite protocol error messages to valid responses, redirecting users to Web servers—ad servers, in the following—that show advertisements or search results hopefully of inter- est to the user. Examples of such protocol errors include HTTP 404 status codes and, more commonly, DNS re- sponses with return code 3 (Name Error), indicating that the looked-up name could not be resolved to an IP address.

這種廣告會干擾消費者，有些供應商提供optout模式，讓消費者不要受到廣告。