If it's not broken don't fix it. I would focus on the top of your funnel to increase sales.
Also, you want to have more annual subscribers than monthly. It's almost certainly more profitable. You're essentially giving up 1/6 of revenue in exchange for guaranteed 0% monthly churn. A simple estimate of what your breakeven monthly retention is: 98.5% = (5/6)^(1/12). So if you're losing less than 1.5% of your customers monthly then this would be unprofitable.
Also, you want to have more annual subscribers than monthly. It's almost certainly more profitable. You're essentially giving up 1/6 of revenue in exchange for guaranteed 0% monthly churn. A simple estimate of what your breakeven monthly retention is: 98.5% = (5/6)^(1/12). So if you're losing less than 1.5% of your customers monthly then this would be unprofitable.