I'm sorry but to imply that housekeepers are so underpaid that it necessitates tipping (as seems to be a huge undertone here) is quite frankly a lie. Housekeepers may be underpaid, yes, but many professions are (educators, police officers, etc), but they're not paid so little that they could not make a living if tips were not involved (unless you're talking about supporting large families, of which I know middle class families who still struggle with this). A friend of mine's mom is a housekeeper here in Las Vegas and her dad is a simple mechanic, yet they still manage to get by, her having just graduated from Notre Dame (not a cheap school by any means) and the entire family having just moved to a rather nice (albeit modest) home on the SE side of town.

In terms of benefits, it's plain and simple. If they're full time, they receive the same benefits that every other full time Marriott employee receives. If they're part time, they receive PT benefits. One additional benefit that is pretty exclusive to the HK department (although an employee in any department can partake in it) is English as a Second Language classes.