I actually dislike it when companies do this because it makes them feel like they've got this "oh look at us aren't we cool and hip, we're basically Google, stay after hours and don't get paid" vibe.
Their evil, the ones corporations buy, are often bought cheap second hand. The longer it sits in the junk yard, the more chance a Mimic has found its new shell. /s
I mean nothing against them in general, but if they are in an office you need to ask is it really just a small perk or is it next to 50 bean bags for in office living.