This. Unless your form is incredibly simple (e.g. signup or login) you shouldn't just rely on placeholder text.

Apple has a nice solution to this issue on their checkout pages - labels placed on top of inputs, only disappearing once text is entered.

I still think inline labels are a bad idea, regardless of placeholder behavior. To quote myself: https://news.ycombinator.com/item?id=4642146

The placeholder attribute in recent versions of Chrome behaves the same way—possibly longer, but I only started noticing it recently—the placeholder remains in the field until you've typed a character.

Also if you filled it out and accidentaly moved back or forward in browser navigation, then go back to it and your browser fills it, the Javascript often removes your text.