[Johndick]

To each their own when it comes to tipping. If you feel she really impressed you and want to show your appreciation through tipping, by all means. Just don't start feeling sense of entitlement simply coz you gave extra $20 to $50, such tip won't be a game changer at all.

For me I don't like all the baggage associated with tipping. If you tip the ML once and don't do it for subsequent visits, it just feels odd, is like she doesn't impress you anymore so you stopped tipping. I prefer to keep it simple and just pay the flat rate and I show my support by RTM regularly. That's just me.

And the fact is whether tipping gives you any clear advantage during booking is anybody's guess. You will NEVER know anyway.