Many lawyers contribute their time to worthy causes, but they are often not aware that they can and should get some benefit from their altruism.
Backlinks (links other websites build to yours) are critically important to search engine optimization (SEO). They are even more powerful when they come from websites (including blogs) geographically close to you, since they boost your rank in Google search results in your area.
You can do well by doing good. However, you have to close the loop. There’s nothing wrong with encouraging the people or organizations you help to recognize this by building a link back to your website.