Good Day,
I currently have a 1GB plan with Linode. This plan has been active since May of this year.
I have been pre-paying my outstanding monthly amounts of $10/month through my pre-paid credit card. Everything seems fine.

I keep wondering what would happen If I forgot to pay on any given month!?
Would my Linode be taken down immediately? Or are they going to automatically deduct from my creditcard? Or is there a deadline payment period?

And If Linode happens to deduct from my creditcard, so what is the point of having this manual pre-paid thing?

I hope any of you experienced Linodians can give me an answer to this. Thanks.

Linode deducts payments from your credit card automatically when you get an invoice. The point of manual payment is for people to pay larger sums at once if desired for switching cards, paying for other people, paying by a certain date, etc. If a payment fails and your account is overdue, we will send you many notices before your overdue services are removed. This typically wouldn't happen for a couple weeks, so we have plenty of time to reconnect with each other and figure out the payment. Extensions are also granted as needed.

Thank you @mkorask for clarifying this. Very much appreciated.