A content management system server can obtain a protocol based data transmission via a computer network from a script that executes at the publisher device server, and can obtain search result content items from an index of electronic documents that include snippets of text extracted from the search result content items and that include hypertext links to the search result content items. The system can extract feature vectors and document identifiers of the search result content items, and can determine information retrieval scores of search result content items. Based on the network identifier, location probabilities of device locations can be ranked and compared to thresholds. The system can determine a confidence threshold representing a minimum degree of certainty of the geographical location of the devices and can select content for protocol based transmission accordingly.