To increase a website traffic, online advertising is often employed. Choosing the right type of advertising and continuously measuring the performance of the campain are essential conditions for success. This is a case study of two advertising campaigns promoting an online food delivery service lakomlacen.si: one on the Google search engine and the other one on Facebook. Online advertising had a strong impact on increasing the popularity of the site and on the provision of its services. Advertising on Facebook attracted more visitors than advertising on Google. On the other hand, advertising on Google brought more desirable visitors, as they stayed on the website longer, visited more pages and placed more orders. Given that the goal of the website is to collect orders, advertising on Google brings better results.