Awesome (accidental) experiment, thank you so much for sharing that! We used to run an AdWords account for a client that was a very famous fashion brand but had just opened an e-commerce website. The CTRs we witnessed were oh so good just because of what you call brand affinity.

Moreover, there is the story of a marketing manager, whose name I can’t recall at the moment, who managed to improve his newsletter open rates dramatically by running right hand side Facebook ads for his audience just for a few hours before sending the actual campaign.