Ad blockers are a challenging trend for online publishers, as an increasing number of individuals use ad blockers. To understand why individuals switch to the use of ad blockers, this research presents empirical findings that explain why individuals develop switching intentions. Based on migration theory, we explain that individuals' intention to switch to the use of ad blockers are grounded in factors that pull individuals to use ad blockers, push them away from not using ad blockers, and mooring factors either hinder switching intention or determine how pull and push factors are translated in switching intentions. We conducted 42 interviews and identified relative user experience, increased performance, improved privacy protection and improved security as pull factors, dissatisfaction with online ads as push factor and computer self-efficacy as mooring factor. This contributes to theory by providing an explanation why individuals develop to ad blocker users.