PTA/PTOs were onboarding loyal Amazon customers via Amazon Smile because of the fundraising. In the last PTO I was involved with, Smile accounted for about 2% of our donations ($3000/year = ~$150K in household spending from our school).
To put that in perspective, about 90% of our $150K annual fund raise was direct donations from parents and local businesses, AND Amazon's contribution was 3 of the 60 MacBook Airs in the One-to-one laptop program our magnet was funding annually. Maybe we judge "effectiveness" on a different scale than Amazon but we sure appreciated their 5% contribution to that program.
Now these organizations will switch all that customer loyalty to Target Red Card.