Using a bank card (whether it's a debit card or a "check card") online is a really bad idea - most banks could give far fewer than two shits about getting things fixed in a timely fashion if you get scammed or something otherwise goes wrong. Which means that during the duration of the error, your money is tied up and can't be used for other things. Indeed, I know of several people personally who have had vendors abuse their debit cards and had the bank turn right around and say "Oh, that's too bad. You'll have to take it up with the vendor. We like overdraft fees, NOM NOM NOM"
Credit card companies, for all their ills, are actually extremely good at proactively detecting fraud and resolving issues. But even when they're slow as shit, it hasn't tied up any ACTUAL money. And that applies to prettymuch any credit card in the universe (except, perhaps, by reputation, those issued by HSBC - which includes the vast majority of store cards. HSBC in general hates the shit out of customers.)
Beyond that, if you step outside the safe, comfortable, accepted-anywhere, bank-issued realm of Visa and MasterCard and look at the cards issued by actual credit card companies (Discover and AmEx) credit cards become extremely useful tools. Discover cards are notorious for having some of the most productive rewards programs in all of creation, and AmEx members get free extended warranties and car rental insurance, and craptons more. They also hand out comparatively higher limits.
Bottom line, credit cards make sense and are a good idea - if you're a responsible enough human being to use them properly.
