Elke did the right thing. I'm sure the server appreciated the gratuity. Yes, servers make $2.13 per hour and know it. But it is also customary to tip in the US. The better the service the higher the tip.
What some seem to miss is, if wages were higher for servers, the price of the food is going to go up.
That tip you give to the server does not only go to the server. That tip is split with the busboy, the bartender, the expediter, the host/hostess, and on charged tips 4-5% to the house. The house has to pay for charge services. And drum roll--Uncle Sam!!!
I used to be a server and my two week paycheck was never more than $10. So yeah, be as nice as you want, but leave the dough.
One night, I remember I was the closing server. White table cloth restaurant in Sears Tower. A Saturday night. Just before closing, a 4 top walks in. The only people in the house for 3 hours. I didn't mind, their check was over $200. And they asked me to order a limo for them. I knew somebody to call as was able to get them a limo at the last minute. Nice people. Paid in cash. As they were leaving the guy who paid the bill and palmed my tip stating how much they appreciated the great service and the limo. Not to be rude, I slipped the money in my pocket without looking and wished them a wonderful evening.
I pulled the tip out of my pocket. He left me $5.00. I still had to tip the busboy, the bartender, the hostess, the expediter (already had left since I had just one table) not the house because it was a cash tip. BUT, it cost me money that night to go to work because it's assumed I'd make between 15-20% in tips. That's what my tip out to the rest of the people I tipped out to expected because that was the house rules.
I became a Flight Attendant soon afterwards. I don't have to rely on tips.