I worked for a manager who had his issues - he was abrupt, impatient and directorial. But if you did something for him, he always responded with "thx".
Some cynics may feel this was simply to acknowledge receipt of the work. Some have said it was simply a knee-jerk habit that held no meaning. Regardless of the motivation (and I believe he was genuinely saying thanks), he said it.
It isn't a raise. It's not a big hug. It doesn't touch the extra hours it took or how I juggled my schedule. It's certainly not a gift certificate for shoes. Heck, it's not even as a good as a handwritten post-it note.
The value is in acknowledging that I contributed - every time.
In this current day of 10-12 hour work days, online language abbreviations, multi-tasking commutes and compressed sleep schedules, things slip. At the best of times, we can only present snapshots of our thinking to each other. In today's craziness, we're reduced to a few choice pixels.
Make 'thank you' one of them.