It's easier to sell the idea that you will get x million this year based on a monthly forecast compared to a yearly forecast.

The question is why do I pay once and not monthly for many services? Because they don't provide bank details and only let me donate via stripe or paypal. Donating 50ct via stripe per momth is just nuts. So, I have to donate 10 bucks once every two years so that We don't pay too much to stripe (and even then stripe gets way too much)