Forget how much of a gratuity to leave the hotel housekeeper, the bigger question is becoming how do you tip hotel staff when you don't have any cash?

The light-hearted question, top of mind for travelers, came up during a panel session at the Toronto Hotel Investment Conference.

"Mandatory tipping: Yes or no?" asked Tony Cohen, partner and executive vice president of Crescent Hotels & Resorts, which manages a portfolio of more than 100 upper-upscale and luxury hotels and resorts in the U.S. and Canada.

Ally Wesson, vice president of marketing for Toronto-based Realstar Hospitality, is against mandatory tipping but noted many brands are testing out mobile tipping apps.

"There have been positive results in some markets and not-so-great results in other markets," said Wesson, asking the audience of 500 if they had any cash on them. "Does anyone carry paper with them? There is very little cash in my wallet. I'm tapping everything with my phone. As a traveler, I would appreciate an additional tipping option."

Read the full article at HotelNewsNow (part of CoStar)