Maybe this is obvious, but the optimal thing for a user who needs your product is to pay for the first couple months, then go yearly once they know they'll keep

Maybe this is obvious, but the optimal thing for a user who needs your product is to pay for the first couple months, then go yearly once they know they'll keep using your product. So it should be expected that most people will be on yearly. There's no reason for most customers to continue on a monthly plan forever. The behavior would be the same no matter the price (unless it's so high that people might sign up monthly once in a blue moon and "batch" their usage then), so I'd only take this as a signal that your product is good and it has loyal customers, not that its price is too low or high per se.