Setting unrealistic deadlines to push your team harder?

Is it better to set unrealistic deadlines to push your team harder or realistic ones?

I have a feel that deadlines are like revenue goals -- you have to set the bar really high in order to get somewhere.

What do you think?

Assuming your team is not stupid, setting unrealistic deadlines is going to stop working *very* quickly - just about as quickly as you'll lose credibility.

Generally speaking, people are motivated by doing a good job. You'll get far better results by not setting deadlines, but agreeing priorities together and letting people figure out how/when they can deliver.

Sure, it's okay to add some pressure - but you must understand the principles of: Cheap, Fast, High Quality - you can have one, maybe two, but never all three.