not sure what this does for growth
I don't think it'd impact growth as much as it could impact churn. If I were to bet, I'd say that 90% of FC users have no idea there's a thing called storage you have to pay for and that your casts will disappear if you don't pay an extra $5 or $8 per year. Many people might get angry once they see it, and since Merkle has $150M in the bank, they can easily cover these costs.