I remember the similar question, but instead IEO it was ICO. What happened many times is that price after ICO drops heavily, and it was better to buy in that time, at lower prices. Looks like same thing happens with some IEO`s, but only with some, not with all of them. Some coins never recover, while some don`t drop after ICO.
What is the smart thing to do here? Well like always when we are not sure in something, we should have careful approach. For example invest just 50% of your planned investment while IEO is ongoing, leave other 50% in case if price drops after so you can buy more.
There are actually a lot of ways to make money here, you can join in some ICO's but as of now ICO's are not good because of the market's condition. There's another you can join, IEO, it is better I think to ICO's. But as of now, I prefer investing in some tokens, buying some more when the price is low just like today and waiting on the right time that the price will rise up and that is the time that I will sell it. I have done mining but I did not go well because I am not getting any money, I don't have better RIG for mining because before you can mine bigger money you need to have bigger video cards also.