I don't know what the service standard is (let alone in the US), but my experience is that every hotel offers the service, while many putting ridiculous restrictions on it (weekdays only, return the next day even if you submit it at 4 AM etc), to the point where I feel they're discouraging people from using them (which seems strange to me, given how overpriced they are). So my suspicion is that the hotels must provide it, but there's a lot of leeway of how it's executed. In any case, not delivering the service within the timeframe stated is wrong either way, service standard or not.