How do you "pay" volunteers?

I work in a very volunteer intensive environment, and we always are looking for ways to show appreciation ("pay") our volunteers. Everyone has a currency they prefer, which motivates your volunteers the most? What's their currency? The first job of a leader is to define reality, and the last job of a leader is to say “Thank You.” How do volunteers experience “thank you” with the most impact?

1. Money
(small increments, gift cards, tokens of appreciation)
2. Private Praise
(specific, pull-you-aside-and-complement, letting them know their service was noticed)
3. Public Praise
(in front of the group, calling them out as the difference maker)
4. Access to their Up-line coordinator/staff
(above and beyond everyone else, they have the up-line’s ear)
5. Input
(their input heard – but they don’t necessarily need their idea to be executed)
6. Knowledge
(they like to be kept in the loop on the inner dialogue)
7. Significance
(they like to be told how your efforts make a difference…the “why” is the motivator for them)
8. Excellence
(they have to be part of something special, an organization that is better than the rest)
9. Flexibility of Schedule
(like to know they are so valuable we are willing to accommodate their schedule)
10. Time Off
(their personal cycle is such that they work hard then hiatus after completion of a goal).
11. Give more work to me
(They are driven by feeling needed).