I have made upwards of 15 investments, some of them are obviously crazy longshots a couple of them have paid out cash dividends at regular intervals. I think it's very important to know that these investments are very long term, not a year but many years. Some of them may never pay back, but there are (in my opinion) a few opportunities on the site that have the chance to turn out incredibly.
Don't make the investment if it is with money you will miss though.