15. The method of claim 11 , wherein said electronic advertisement and target content comprise different vocabularies, said first and second content match features providing a translation between said electronic advertisement and target content vocabularies.
11. A method of determining relevance of an electronic advertisement to a target content, said method comprising: extracting a set of terms from said electronic advertisement and said target content; calculating a first content match feature using said set of terms, the first content match feature comprising a translation evaluation feature indicating a degree to which n-grams of the electronic advertisement and the target content match; calculating a second content match feature using said set of terms, said second content match feature comprising a translation proportion feature indicating a proportion of related terms in the electronic advertisement and the target content; and processing said first content match feature and said second content match feature with a machine learning model to output a relevance score indicating the relevance of the electronic advertisement to the target content, the machine learning model comprising individual weights for the first and second content match features, the machine learning model being trained using said first and second content match features and machine learning techniques.