Very good question. I also do not know exactly why new projects spend so much money on advertisements. In cryprocurrency, advertisement is worth it? It there any set criteria that binds a project to collect only a certain amount of money? or one can collect as much as it can? But I think cryptocurrrency is such platform where advertisements rule and without advertisements, you can not get the attention of traders and investors. That is why I think it is a bit different from stock market. It is decentralized and it is for all people around the world.
That is because, they are thinking for a long term investment back from their project. The best way to do that is to strengthen their marketing, and even the profit is not really obtained on the ICO stage, once their project has been launched, there, the profit will going to be steady. They will need just to be successful in funding their project initially.