Abstract: Systems and methods for categorizing web pages and using categorized web pages are provided. The categorization involves using at least a master word list and one or more category word lists. The master word list tracks all words encountered by the system (except with the possible exception of natural words) and the category word lists includes words associated with a particular category. These lists can be initialized in a training phase and then the one or more category lists can be used to identify words in web pages matching words in one or more of the category lists. Based on this matching, as well as based on the master word list, a weight is generated for the web page, which is used to determine whether the web page belongs to a particular category.

Abstract: Systems and methods for view-based advertisement selection involve controlling the rotation of reproduced advertisements based, in part, on whether the reproduced advertisements are within a browser viewport. An advertisement that is reproduced on a web page and is not within a browser viewport can continue to be reproduced until the advertisement is within the browser viewport for a period of time. After an advertisement is within the browser viewport for a period of time another advertisement is selected to replace the previously reproduced advertisement.

Abstract: Systems and methods for view-based advertisement selection involve controlling the rotation of reproduced advertisements based, in part, on whether the reproduced advertisements are within a browser viewport. An advertisement that is reproduced on a web page and is not within a browser viewport can continue to be reproduced until the advertisement is within the browser viewport for a period of time. After an advertisement is within the browser viewport for a period of time another advertisement is selected to replace the previously reproduced advertisement.