By buying recycled products from old circuit boards, you are helping to reduce the impact of waste that would otherwise fill up all those landfill holes in the ground. The energy to produce a product from recycled material is also significantly less than making virgin material.
The added bonus of buying this from Oxfam is that all of the profit goes to fighting poverty around the world and minimising the impact of Climate Change on the poor, who are often the hardest hit. So it's a great big beneficial circle.