I think I've just clicked what I was doing wrong. People coming to my site already knew what they wanted because they'd been channelled by my youtube videos, so were distracted by the opt in and less likely to buy. What I need to do is aim the freebie/opt in at people who haven't come across the samples on a page away from the place where the warmed up customers come. Is that right? And any ideas how I would get to these people?