Pool donation ethics - tipping your pool.

[3Dfilament]

So you are mining Crypto Currency coins at a pool, how much should you tip? If a pool fee is charged already, what might you base any additional donation, above and beyond the imposed pool fee, what might you base an increased donation upon?

If the pool charges no fees, what then will you base your donation amount upon?

[lukemarshall]

Usually the going rate is 1-2% so I hear

[3Dfilament]

Usually the going rate is 1-2% so I hear

If your stales/invalids were averaging 4-5% at one pool and the donation rate you were giving them was 1%, but the stales/invalids at another pool were on average 2.5%, how much more in additional donation might you be willing to give the second, more efficient pool?