The other obvious issue is the cable construction quality. I've had a few £1 cables and they've not be the best in terms of not falling to bits after being moved a few times.
But otherwise as everyone has said - HDMI logo = job done or it's faulty.
I've found these pretty good construction wise and at a fiver, you can't really go wrong. It's worth factoring in if you unplug cables a lot - I know I do!