"ecommerce sites are making it as difficult to buy products as humanly possible." If my credit card has a number as four blocks of four digits then I expect to

"ecommerce sites are making it as difficult to buy products as humanly possible." If my credit card has a number as four blocks of four digits then I expect to type four blocks of four digits. A webpage with <input limit=16> is wrong. This was easy to fix in 1998 and it is trivial to fix, client side and server side, in 2008. This isn't academic. This increases support and it costs sales. If I encounter this case then I take business elsewhere. If they cannot get this issue right then how I trust that they'll fulfil my order? I'm not being petty but if this issue is apparent then testing isn't sufficient and they're not acting on feedback. In either case, this is evidence that they're less likely to send the correct products first time, less likely to fix mistakes and less likely to give a refund.