Techniques are provided that include obtaining a Document Object Model of an HTML document, such as a web page of a publisher. Elements of the Document Object Model may be identified that are associated with native advertisement placement candidate containers. Based at least in part on analysis associated with the Document Object Model, and utilizing at least some of the identified elements, one or more native advertisement placement candidate containers may be determined. Some techniques may utilize, in the analysis, construction and utilization of a suffix tree of a string of tags comprising all tags in the Document Object Model. Some techniques may utilize, in the analysis, a node flattening technique in connection with the Document Object Model.