Well we can't force someone if that is the only amount he has for investing. And of course not all investments are going to be on get amount immediately. And that is a good amount for starting so that if ever you are not going to be successful at your first investment then you afford to lose that amount and you are not going to feel sorry about it.
It depends on you if how much profits you want to get from a business and you will have to invest accordingly, but in this case it is not important at all because OP is just looking make it grow but he is not saying how quick or how long it would or should take for it.
Well for me there are two types of investment that you are able to make with that amount is that you are going to invest with trading or you are going to invest in online casino' many are getting it right when they are reading 'to invest with casino' they tend to think that you are going to gamble. It is like you are going to be an investor to their site.
investing on an online casino would be great if you have a huge amount since you would have percentage profit out of your investment through their site but remember that there is still risk on lossing all your money because every investment has its own risk.