It's one of my pet hates. I find a website full of really interesting stuff, and decide I might buy something. But there's a catch; you have to register with them. Why ?
It means they get all my information - name, address, possibly telephone number or date of birth, or whatever other daft questions they add to the registration form. It even means they could get a password. For many people, one password opens many doors, but luckily I'm a touch paranoid about internet security and never use the same one in more than one place. If you buy something, they can then tie all this data to your credit card details.
Although the vast majority of online retailers are honest, and many will have even done the right thing and registered with the Data Protection Agency, there's always a risk that the data could fall into the wrong hands. It only takes one virus or one visit to a dogdy PC repair shop ! Not that I blame the retailers; many of them will have handed their website development to IT companies who are great at making flashy websites, but can be somewhat less switched on about what makes customers want to go shopping.
So on our website, I code it myself and make sure we avoid all that. Customers can just hit the buttons and add stuff to the basket. I never see the credit card details (they are handled entirely through a secure Paypal checkout), and the only info I get is just what's needed to post the orders off and maybe a voluntary subscription to our mailing list. Just in case, I also spend a good amount on multiple layers of the best antivirus & anti-spyware software I know of (did I mention that I'm pretty serious about online security...).
All this means that the buyer's experience is as worry-free and smooth as it's possible to make it, and I hold very little information so there's no worry of it getting into the wrong hands. Oh, and I never, ever, ever pass details of our mailing list subscribers to marketing companies !
In the words of a certain TV-personality meerkat.... "Simples !"