7. The method of claim 1 further comprising: detecting an occurrence of a first cursor event at the first client system, wherein the detection of the first cursor event includes detecting a location of a cursor at the first display being positioned over a portion of displayed content representing the first specific portion of modified web page content; and causing the first client system to automatically display, in response to detection of the first cursor event, a first pop-up window or layer which includes a first portion of advertising content that is different from the first specific portion of text.
7. The method of claim 1 further comprising: detecting an occurrence of a first cursor event at the first client system, wherein the detection of the first cursor event includes detecting a location of a cursor at the first display being positioned over a portion of displayed content representing the first specific portion of modified web page content; and causing the first client system to automatically display, in response to detection of the first cursor event, a first pop-up window or layer which includes a first portion of advertising content that is different from the first specific portion of text. 9. The method of claim 7 further comprising: selecting, using at least a portion of the scoring information, advertising content to be displayed at a first client system; and causing the first client system to automatically display a first pop-up window or layer which includes the selected advertising content, wherein at least a portion of the displayed advertising content is different from the first specific portion of text.