I have been to a few myself, and I can tell you that it depends on the size and what you are going there for. If you actually do have something that you can make money from, and you are going there to make a sale, there is a possibility that you could make some money there. It could be a project, it could be a website, it could be an affiliate marketing thing, it could be a software, anything really, as long as you make a sale. But if not, and you are just going there not knowing what you are going to do and just walking around, then you may meet a few cool people but that's it, nothing else will happen.