In accordance with embodiments, there are provided mechanisms and methods for providing apportioning of opportunity among campaigns in an on-demand service in a database system. These mechanisms and methods for providing apportioning of opportunity among campaigns can enable embodiments to automatically determine which campaigns are related to an opportunity and provide a filtered set of campaigns that are related to at least one opportunity. The ability of embodiments to apportion opportunity among campaigns can provide marketing information that accurately reflects the true relationship between an opportunity and a plurality of campaigns.