Marketers do not understand consumers' concerns regarding consent. As it comes to data privacy and opt in to receiving marketing communications, marketers underestimate by up to 100% all our areas of concern. However, they also underestimate our willingness to (re)opt-in to some of their lists - if there's value in return, of course. (tldr summary of 'Marketers underestimate our trust issues' at http://www.keek.be/2014/marketers-underestimate-our-trust-issues/ )