Treating your users as co-developers is your least-hassle route to rapid code improvement and effective debugging.

That stupid people are more violent is a fact independent of skin color.

In the U.S., blacks are 12% of the population but commit 50% of violent crimes; can anyone honestly think this is unconnected to the fact that they average 15 points of IQ lower than the general population? That stupid people are more violent is a fact independent of skin color.

Ugly programs are like ugly suspension bridges: they're much more liable to collapse than pretty ones, because the way humans (especially engineer-humans) perceive beauty is intimately related to our ability to process and understand complexity. A language that makes it hard to write elegant code makes it hard to write good code.

Good programmers know what to write. Great ones know what to rewrite (and reuse)

The Wesnoth devs are good but not exceptionally so, and we're weighed down by a crappy implementation language (C++). Nevertheless our productivity, in terms of goals achieved per hour of work, is quite high.

If you treat your beta-testers as if they're your most valuable resource, they will respond by becoming your most valuable resource.