The hype and only. If the token is well known that means the price will rise and I may get a profit. If the project is a dark horse I would think twice before investing ... and certainly won't invest in it.
Do you mean the token that the ico might be using/based on? Or are saying hype of the project itself? I guess any investment in an ICO would likely come before or extremely early I to any hype generation. If there was a ton of hype, likely the project already satisfied its ICO and is moving towards (hopefully

) going live.
Thanks!