Giving away so much discount to their target investors and promising a big exchange.
This are the basic promise of those scam ICO, BUt that are just speculation.
We will always see those scammers at the end if their ICO.
True! Never invest in the project that gives discount on time basis. As soon as coin is listed on any exchange, early birds dump their coins and coin never recovers such dump.
However, it is wrong to say that such projects are scams, it is just that their marketing strategy is poor.
The easiest way to detect if project is scam is by looking at the team. It is easy to detect whether team is genuine or fake. Also previous experience of the team could be checked.