Donate Gold

Donating gold to Zin (via the ability) adds piety to a seperate pool (capped at 30,000 extra piety).
With every action you take, there is a 1/5 chance for a point of piety to move out of this pool into your actual piety.
The game does not roll or take away piety if you are at max piety, and the piety pool is not subject to piety decay.
Note: piety decay works off global aut, not number of actions.

If you ditch Zin, even for a good god, your piety pool is emptied.

The amount of piety you get for donating N gold is floor(N * log2(N) / 200).
If you donate 38 or less gold, Zin "finds your generosity lacking" and steals your cash for nothing.
Generally, bigger donations are more efficient, but being close to a breakpoint is more important for smaller amounts.
Some breakpoints, to give an idea of how much gold maps to how much money:

39+ gold: 1 piety
67+ gold: 2 piety
92+ gold: 3 piety
117+ gold: 4 piety
141+ gold: 5 piety
164+ gold: 6 piety
186+ gold: 7 piety
208+ gold: 8 piety
230+ gold: 9 piety
251+ gold: 10 piety
273+ gold: 11 piety
293+ gold: 12 piety
314+ gold: 13 piety
334+ gold: 14 piety
355+ gold: 15 piety
375+ gold: 16 piety
395+ gold: 17 piety
415+ gold: 18 piety
434+ gold: 19 piety
454+ gold: 20 piety
473+ gold: 21 piety
493+ gold: 22 piety
512+ gold: 23 piety
531+ gold: 24 piety
550+ gold: 25 piety
569+ gold: 26 piety
588+ gold: 27 piety
606+ gold: 28 piety
625+ gold: 29 piety
644+ gold: 30 piety
662+ gold: 31 piety
681+ gold: 32 piety
699+ gold: 33 piety
717+ gold: 34 piety
736+ gold: 35 piety
754+ gold: 36 piety
772+ gold: 37 piety
790+ gold: 38 piety
808+ gold: 39 piety
826+ gold: 40 piety
844+ gold: 41 piety
862+ gold: 42 piety
880+ gold: 43 piety
898+ gold: 44 piety
915+ gold: 45 piety
933+ gold: 46 piety
951+ gold: 47 piety
968+ gold: 48 piety
986+ gold: 49 piety
1003+ gold: 50 piety
...
1177+ gold: 60 piety
...
1347+ gold: 70 piety
...
1515+ gold: 80 piety
...
1681+ gold: 90 piety
...
1844+ gold: 100 piety
...etc.