Tell HN: Free Refills with This Tumbler

Background: At this point in my life, I roll out of bed and get coffee from Dunkin'. Large, black, hot. It's like $4. I'm not happy about it, but I swipe and go on with my day.

The bagel shop I go to has a $15 tumbler that you can get free refills with. I love this because a cup of coffee anywhere is like $3 and it's all margin. My new routine is go there, get a bagel with a spread for like $4 and get coffee.

I'm ahead cause now I have coffee and food. They're ahead because they're not even trying to compete with coffee shops. They just give away the free stuff. I've made my money back on the tumbler and they keep making $4/day off me.

What's the software equivalent?

Differences: coffee has non-zero cost everywhere. software has zero cost with ads. If I give away coffee, that brings people to my store. If I give away software, will people buy something to go with the free software?