According to The Register, ‘Google has filed for a patent that covers advertisements in syndicated content’. Application No 20050165615 concerns a method for ‘Embedding advertisements in syndicated content’:

‘Syndicated material, eg, corresponding to a news feed, search results or web logs, are combined with the output of an automated ad server. An automated ad server is used to provide keyword or content based targeted ads. The ads are incorporated directly into a syndicated feed, eg, with individual ads becoming items within a particular channel of the feed. The resulting syndicated feed including targeted ads is supplied to the end user, e.g., as a set of search results or as a requested web log.’

‘Embedding of targeted ads into syndicated feeds and/or user response to the embedded ads is be tracked in an automated manner for billing. The automated targeting and insertion process allows ads to be kept current and timely while the original feed may be considerably older’

Source: The Register