Dear All,
A suggestion.
On other forums (fora?) there is often a "thank you" button to click on that immediately thanks the person who has posted to help you. The "thanks" are totalled and displayed.
Being a simple button, people tend to use it rather than having to either (a) than folks in the open forum (no bad thing mind, but it takes extra time and effort and consumes storage space on the servers) or (b) thanking people via a PM (which, I find, is something that you cannot do unless you have a post count of at least 30 (for some very strange reason I've yet to fathom).
Just an idea,
Art