The Tl;Dr here is that the cost to them of operating the free tier is lower than what they estimate their Customer Acquisition Cost would be without a free tier, so the free tier generates better leads/conversions to their paid products at a lower cost than traditional sales and marketing.
As long as these economics continue to hold they'd be stupid to discontinue the free tier.
But it isn't 'economics' as there is no actual data or science here, just a wild guess about what customer acquisition might currently cost. All it takes to rug pull is some exec speculating that 'the economics' have changed.
All it takes is for the decision-maker who gets the credit for cutting costs by removing the free tier to be a different person from the one who gets the blame for higher customer acquisition costs. Not saying it'll happen, just that it being a bad move isn't a guarantee.
Makes me wonder.
Say 5% of the free tier users converts to a paying customer within 5 years. And user growth is constant. Then over time, you will get a much larger free tier user base, compared to your paying customers (in absolute numbers). At some point, it must become tempting to charge all free tier users a little bit to continue, because the group got so big, so there is a lot that can be earned there.
Is this wrong, or should we expect this?