justin2877 Hi there,
I've just spotted this thread. I hope you don't mind me removing the Best Answer you had set, however it unfortunately wasn't fully correct.
So - one major misconception here is around how we calculate Payback. We most certainly do not calculate it based on quantity of posts made. The calculations are actually quite complicated, and there is no specific amount of Payback awarded for any single post.
One of the key elements of the Payback calculations we run is that there is a set monthly budget. We then assign that budget to members who have been active on the community according to a range of factors - activity on Labs, activity in the Help and support tag, activity in general across the community that has proven to generate 'engagement' within the community.
It's the set monthly budget that ensures it is sustainable. You could make 19 posts every month and not get the same amount of Payback each month, depending on where those posts were made. Every member who is active across the community receives 4 'scores' that helps determine how much Payback they will get.
There's a discussion from 2015 (when the current system was put in place) that you can read to get more detail: https://community.giffgaff.com/d/16650918-community-payback-2-0
Unfortunately the formatting of that post has been lost when we migrated to the new community platform, so I'll see if I can tidy it up a bit - but it's still readable.