Systems, methods, and computer storage media having computer-executable instructions embodied thereon that facilitating keyword extraction for advertisement selection. A set of performance indicators that indicate performance of a keyword in association with one or more advertisements is referenced. A determination is made as to whether the keyword is a noise keyword that is relevant to web content and results in a low click rate or a low impression cost. The set of performance indicators and the determination of whether the keyword is a noise keyword are utilized to identify a keyword type of the keyword, wherein a keyword type can be a positive keyword or a negative keyword.