When it comes to financial and materialistic gains in business, it still surprises me on how one can constantly take things from others without giving back in some way. There was one conversation I had with a person who wanted help for commercial reasons without having to pay anything as according to him it should be a very easy thing to do anyways.
From my experience, it never turns out too well when a person keeps asking you to do things for them knowing well that you lose money in the process. Of course that is not to say that you should always expect something in return if you are doing a good deed. Generally speaking though, anyone that constantly asks for something without giving back are usually the first ones to look the other way if the situation was reversed too.
With that in mind, sometimes it just makes more sense not to excessively surround yourself with those types of personalities both from a business and personal stance. There is a difference between doing a good deed and being taken advantage of.