The most important thing – keep your cool, breathe, count to 10 and then answer a difficult question. Remember – they are watching to see how you deal with challenging questions even more than the answer! Having competition is a great thing really – you just need to be able to identify what truly sets you apart from our competitors. Group them into 3-4 types, explain briefly what each type does with a few examples of the main competitors and then say how you are different/better/doing more without bashing your competitors 🙂