It's the same with absolutely everything. How many people give money to charities, how many help them by volunteering. How many people actually take times in politics to get involved into parties, march the streets or leafleting. Etc.
Your comment reminded of something I was taught by my economics professor, he told us about small things can add up and gave the example of giving to charities. So when I started working I started giving like a couple percent of my income to charities. Now over the years it really has added up in total.
