When it comes to accepting volunteering non profits can always take more, but unskilled volunteering may not work out 100% of the time in the long run. Unskilled volunteering can always be used, but as the non profit grows it will need more volunteers that know what they are doing, and that is when the skilled volunteers come in.
What makes a non profit ready to accept skilled volunteers is the plain fact that unskilled volunteering isn’t quite cutting it anymore. They need people who they don’t have to pay, but know how to do what it is they need them to do, without training. This usually happens to a non profit once it has reached a larger more concrete organized level, when it can afford to turn certain volunteers away due to their lack of experience in a certain area. It’s not so much that they don’t need their help, but that they need someones help who is skilled in a specific area so they can just come right in and start working on it. An example could be accounting, or social media managing. The non profit is at the point where they don’t quite have the funds to employ someone to do those kinds of things for them that are part of expanding process, so they turn to skilled volunteers.