Abstract: The invention relates to a method, and associated system, of determining contextually relevant advertisements to serve to a web page, the method comprising steps of providing a content database of content associated with web pages; storing keywords having bids associated therewith, the keywords being associated with advertisements; storing a plurality of advertisements associated with different keywords and/or advertisement-keyword combinations; analysing a web page and extracting prominent terms therefrom; comparing each extracted prominent term with keywords stored in the keyword database and/or advertisement-keyword combinations to determine and store a relevance score for each identified keyword; searching all content stored in the content database for each identified keyword having active bids, assigning and storing further relevance scores to identified keyword respectively in terms of a relevance to the content stored in the content database; and using the stored relevance scores for the identified key

Abstract: The invention relates to an online advertising system comprising an activity determining module configured to determine, via a channel setup module, browsing activity on a web page comprising the channel setup module; a content database storing content associated with a plurality of web pages comprising channel setup modules; and an advertising server configured, at each determination of browsing activity on the web page, to determine whether recent content from the web page is substantially stored in the content database, wherein if the recent content from the web page is substantially stored in the content database, the advertising server is configured to serve an advertisement to the web page. The advertisement served advantageously selected after operation of a forward matching module and a reverse matching module to that the advertisement served is contextually relevant to the web page. The invention also relates to a method of operating the online advertising system.