Speaking at DMA 2012 this week, Worldata CEO Jay Scheweldeson presented conversion data on mobile email, which indicated that tap errors - or clicks on the wrong link because of a design not optimized for mobile, which send subscribers to the wrong page - reduce conversion by 28%. Scheweldeson pointed out that the adult finger covers 45 pixels on a mobile screen, and that call-to-action buttons should have 15 pixels of padding in order to mitigate the occurrence of tap errors.