Abstract: A method of dynamically expanding an online advertisement campaign in a VR environment comprising: receiving an advertisement request from a website loaded by a client device for VR presentation a VR environment on a VR display to a user using a VR user interface to navigate in the VR presentation, the advertisement request comprises a request to present an advertisement items to the user currently presented with at least a portion of a certain page of the website, selecting a presentation location in the page for embedding a presentation symbol correlated with a selected advertisement item and responding to the advertisement request with an instruction to embed the presentation symbol in the presentation location. Wherein the presentation location is selected to be discoverable by the user according to a discovery difficulty level calculated based on campaign parameter(s) defined by campaign rule(s) extracted from a campaign policy associated with the website.