Also the entire click & buy thing makes one worried. I find myself thinking "What kind of company did I just let you guys talk me into giving my credit card information to?". The fact that they actually charge your account small amounts of money in order to just "verify" it isn't exactly reassuring (sure it's added as store credit but as I'll likely not ever use that account that's some lost money).
Paypal does this for certain transactions, too. It's just that they're more transparent about the whole thing, and you end up accomplishing what you meant to do in the first place.