Some circumstances, we have to receive something in return, such as when our business is a product or service, our survival depends upon it.

But when we do indeed have an abundance, then we benefit by sharing. Sharing is thus giving with out expectation of return.

Things such as sharing information are more or less an unlimited abundance. Hence the explosion technology development and the advancements in science.

Open Source software exists on the very principle embodied in your last sentence.