Important that 20% time can be beneficial to your entire team. And this doesn't have to be absolutely free, it can be tangentially related to something that at

Important that 20% time can be beneficial to your entire team. And this doesn't have to be absolutely free, it can be tangentially related to something that at least sort of aligns to your company - whether internal (support, communication, internal fun) or external (product, trying new platforms / technologies). And it doesn't have to start at 20%; if your core product can't afford everybody to take 20% time toward interesting things, then 10%.