forgive me the 14:09 GMT triviality, but most of us are creature of habit - so I know plenty of avid readers who swear by the superiority of paper. Until they try an ereader, in which case most (but not all) are swayed. Especially now that you can read regardless of the environmental conditions (light, water, sand, you name it), how can anyone not be won over by the convenience?
Of course there are still books that make more sense in paper form or on a tablet (art for instance) - but to win someone over I'd recommend lending your own ereader: if you can bear the thought, that is