Mobile marketing has changed a lot over the last ten years due to the dramatic changes that mobile phones technology has gone through. Mobile advertising expenditure has been consistently increasing, yet this budget increase does not reflect in ads’ effectiveness. In order to address this issue, the aspect of intrusiveness must be taken into consideration and since there are very few studies on this matter the task becomes even more challenging

The purpose of this thesis is to understand how perceived intrusiveness through the factors of ad-context congruency, size and animation influence consumer attitudes in the mobile medium.

In order to fulfill our purpose, the method was based on a qualitative approach with semi-structured interviews where two stimuli per each factor were presented to all the interviewees.

This study concludes that mobile ads cause irritation on smartphone users and as a result are considered ineffective. Regarding the factors of intrusiveness, incongruent, big and animated ads are considered more intrusive than the opposites because they affect task performance and thus generate more negative attitudes. This study also concludes that context congruency is the most essential factor among the three of them.