I would ++ this twice (on the strength of the first para). For years I've taken a very long-term approach to my online posting, being well aware that my answers are potentially useful to orders-of-magnitude more people than read the particular forum it's posted in.
The reason for taking this attitude is simple: I can't count the number of times I've whacked a question into Google and been saved an hour (or more) of tedious debugging. I'd much rather have that hour of my life to, say, drink beer, and I'm sure others would too.
"Half of all adults in the United States say they have registered as an organ donor, although only some have purchased a motorcycle to show that they're really serious about it."