[the_af]

My experience is the opposite: I've never used a PIN.

I've done some reading and now I believe it depends on the country which issued the card (as opposed to the country where you're using the card). So if you have a card issued in the US and Latin America, you probably won't asked for a PIN -- because you don't have one -- and instead you'll be asked for id and your signature. If you have a card issued in Europe, you'll be asked for a PIN.

Interesting. A PIN seems safer than a signature to me, or possibly the combination of chip + PIN, but it simply doesn't get used where I live.