Smile is really just a way to get additional value from donations large companies have to make anyway for lobbying and tax purposes.
They would've happened anyway, but you get to direct it. Maybe they can sell the data it generates to identify areas or people more likely to donate to charity, and sell that data to fund raising companies.
And maybe (new use case!) they can use it to reduce opt-outs of notifications, which carry associated value.
I can envision the notification product owner reaching out to the smile team with this new opportunity. "Hey, you have this cool feature, I really think it could help here!"