Most don't take a salary. Remember most of these ICOs are start ups. Most have zero seed money, hence they do an ICO to raise funds. There will be a certain number if tokens allocated. They just split the coins that have been allocated to the team. On the ICO s I have seen its usually 10% to 20% of the total tokens. So in the end it all depends on the success of the project. It it does well, then the tokens are worth a lot... If not, the tokens aren't worth much.