The Swedish consumers are concerned of their online privacy, while companies increasingly gather personal information with business intelligence (BI) technologies in order to customize online banner ads, among the favoured marketing techniques. Meanwhile, marketers treasure the opportunity to target individuals. The purpose of this research is to generate insights of Swedes’ experiences of intrusion of their privacy online, and their behavioural response to personalised banner advertisements. The research will also observe if there are differences depending on the consumers’ ages. Mediating factors will be regarded how they influence the online users perceived intrusiveness and usefulness of personalised ads. The study is exploratory and aims to provide extensive awareness and beliefs around a complex phenomena. It will have a qualitative approach where data collection is conducted through semi-structured, in-depth, interviews with Swedish consumers from two age groups, complemented by three expert interviews. The results show that, in comparison, elderly consumers have less knowledge of personalised advertising, as well as BI-technology, leading to higher privacy concern and perceived intrusiveness when exposed to these ads. Members of the generation Y comprehend the phenomena to a greater extent, and more easily see the usefulness presented, but are overall ambiguous. Attitudes are likely to be formed based on the experienced intrusiveness contra usefulness, but are not clearly influencing trust, loyalty of future purchasing behaviours. Generally, marketers and consumers’ views show incongruence, as marketers remain very positive to using personal information to customize ads, while consumers do not always perceive it similarly. A balance can be difficult to achieve, but a unanimous belief demand high accuracy of content and placement of the personalised ads to be perceived as useful.