she isn't getting one every day.
Googlers get massage credits once a year (for 30 minutes or 60... I don't know I've never used them), and are still required to tip even when the massage is "free".
Massage credits are also passed around kind of like cigarettes in prison--but I guarantee you she isn't getting more than 1 massage per month. And if she is, she's spending a lot of money on it.
Take away the massage and you're at 8 hours