We tip, often and generously, and it's some of the most fun I have on our trips!
We checked in to CR on the 12th and I left a tip for turndown service and the regular housekeeper the next morning before we left for the park. When we came back, the room was squeaky clean, beautifully turned down and there was a HUGE mickey head made of towels on the bed. So exciting!
The next day, we went to breakfast then dashed back to the room for something we'd forgotten. It was fortuitous because we ran into our WONDERFUL housekeeper. I was so glad we got to meet her.
We chatted with her a lot, and after she thanked us profusely for the tips we'd left already (we leave $5.00 in the morning and the same amount for turndown CM) she said that she'd noticed the envelope for turndown the day before but saw that they hadn't added us to the list. So she took it upon herself to turndown the room while she was cleaning so we wouldn't be disappointed! She also said that she'd had a ton of checkouts to do that morning but she wondered if we'd come back to the room for a break in the early afternoon so she made up our room first thing.
I asked her about tipping, and after some prodding, she told me that of eight check-outs she'd had that day so far, NO ONE had tipped her. Not one. And these guests had stayed for a WEEK!
She said she observed that it was the "working class people" who left the best tips and that they also usually left the rooms less messy, she joked about some rooms she saw that she just wanted to run away LOL. She said people there for conventions almost never left tips

Thinking about how many we saw there during our trip, that made me sad and angry considering a lot of them are there on expense accounts!
We tipped her a little extra the following days. She was really extraordinary at her job, my room had special medical requests and every one was met and exceeded. She left towel animals, at least one, sometimes two, EVERY DAY. She did everything she could to make things amazing and she was the best housekeeper we have ever, ever had at WDW.
She made our trip magical and I like to think maybe we made her week a little better with the extra income. She's somebody's grandmother (we talked about our families) I know if it was my grandmother working so hard to clean at a luxury resort, I'd appreciate if people tipped her.
It really does make their lives easier. Also, it's interesting to note that at DL housekeepers are listed as a tipped position. I wish they'd list them as such for WDW too.
I consider it thank you for all the pixie dust they sprinkle on me during my stay

and I swear, I've only had ONE towel animal on any of my previous trips even staying at the GF...to have more than eight in six nights was incredible!