9. A computer-based promotion content distribution system, comprising: a lexical analysis portion configured to obtain a target text and to analyze lexically the target text; a hierarchical classification portion configured to extract features, comprising traffic feature, from the target text and to classify hierarchically the features extracted from the target text based on a pre-trained hierarchical classification model considering traffic feature to obtain a hierarchical classification of the target text; a content promotion portion configured to select one or more among a plurality of content items based on the hierarchical classification of the target text, to obtain the selected content items and to push the obtained content items to a terminal; wherein the target text comprises a webpage text which comprises a traffic feature identifying source of the webpage text; wherein the plurality of content items comprise a plurality of promotion texts; wherein the lexical analysis portion is further configured to: for each of the plurality of promotion texts, obtain the promotion text and analyze lexically the promotion text, wherein the hierarchical classification portion is further configured to: for each of the plurality of promotion texts, extract features comprising traffic feature from the promotion text and classify hierarchically the features extracted from the promotion text based on a pre-trained hierarchical classification model considering traffic feature to obtain a hierarchical classification of the promotion text, wherein the content promotion portion is configured to: for each of the plurality of promotion texts, calculate similarity between the webpage text and the promotion text based on the hierarchical classification of the promotion text and the hierarchical classification of the webpage text; and select one or more among the plurality of promotion texts based on the similarity between the webpage text and each of the plurality of promotion texts.
10. The system of claim 9 , in which the hierarchical classification portion is further configured to extract from the target text at least one of the following features: token, keyword, topic, general keyword, expanded keyword, named entity of the target text.