I would invest in anything non-ponzi (unless at the beginning) and nothing (just keep bitcoins).  Also not to forget to invest in yourself (schooling, etc).  Unfortunately you have to go high-risk, high-reward until you have a decent amount of money to just keep revenue at a certain level, but reduce risk.  If you want to invest in a business you can't until you have a lot of upfront money, so you should invest in other businesses that you think will succeed until you can earn the capital required to start your own.