As a user it's often the difference between me buying and not buying (having to go through finding my card, entering the information) when buying online. If I c

As a user it's often the difference between me buying and not buying (having to go through finding my card, entering the information) when buying online. If I can click "buy" and it's done then I spend much more money. I've spent what must be over $5,000 via itunes (the majority of it being music and film/tv though, not apps) and I would never have spent that much if I had to enter my information every time. I don't think it makes a difference on desirable purchases -- things I actively decide "I want this!" and then seek out -- but on impulse buys it's the difference between a sale and no sale.