Think of it not as "donating", but as crowdfunding for an enterprise that both you and other people might care about. If you donation match, you incent others to pitch in for the effort, because they can "leverage" their own donation. And of course, this incentive effect is a kind of leverage from your own POV as well. (There used to be a _formal_ proposal for a 'fully decentralized' form of donation matching as crowdfunding for public goods at https://snowdrift.coop, but I'm not sure if that effort is going anywhere...)
Think of it not as "donating", but as crowdfunding for an enterprise that both you and other people might care about. If you donation match, you incent others to pitch in for the effort, because they can "leverage" their own donation. And of course, this incentive effect is a kind of leverage from your own POV as well. (There used to be a _formal_ proposal for a 'fully decentralized' form of donation matching as crowdfunding for public goods at https://snowdrift.coop, but I'm not sure if that effort is going anywhere...)