Systems and methods to provide advertisements based on the content of documents in which the advertisements are presented. One embodiment includes: a web server to receive a request for an advertisement in reference to a document provided to a user by a content provider; a backend server to identify the advertisement based on relevancy of the advertisement to the content of the document and to associate a communication reference with the advertisement and the content provider, the web server to provide the advertisement and the reference for inclusion in the document; and a telecommunication server coupled to a session border controller and the backend server to receive a connection request via the reference, to determine contact information of the advertiser and identify the content provider based on the reference, and to establish the connection between the user and the advertiser using the determined contact information.