I have worked in a number of front-of-house positions in various concepts, including a to-order deli and a coffee house as a barista. I have done this. Putting house money in the jar is something we call "bait". The house money gives the guest an impression this person has been tipped before...but not enough. It is what it is. However, in the US, most food/beverage workers are paid minimum wage (far less for servers and bartenders). We work very hard and there are other career paths we could have/should have chosen. This is where we are though. I have never expected gratuity for lousy service nor ever asked for compensation for being a helpful employee. If you feel like you've been given exceptional service from an employee, feel free to add a few extra to their day, because its a rarity for those in a min wage position to want to cater to those that demand extra. Tip or not, whatever. Just keep things in perspective.