Most of the altcoins start with a crowdfunding and with investing (ICO) at most of these funds are accumulated in bitcoin.
By this not only that these altcoins become popular but also bitcoin become more popular because through bitcoin they are investing in another cryptocurrency.
Indeed. Maybe doubling bitcoin could be possible in investing with altcoins. They have been looking for a way to double it, it might not be that fast but it could happen if the invested alt will really shine.
I haven't invested in any ICO but it contains the risk, because the price after the ico can drop and you can lose.
But also it is a good opportunity to make a profit, I saw many coins that their exchange rate was way to high than the ICO price.
if you invest into an ico you should always remember that the risks are huge, thats why i never do such investments because i would lose money